MOA with the 30-06

[x101airborne]

About a month ago, I decided to dedicate my mauser 30-06 to a CAST ONLY shooter. Now, this rifle will do well under half inch for 3 shots at 100 yards with J-words, so I know the weapon is up to the task. Scope is a Leupold 30 mm long range 4.5-14x40 with fine duplex reticle and side focus.

I started out with a freshly resized, once fired bag of 50 Winchester Nickle brass. All had been fired in this weapon, full length re-sized, and primed with Winchester large pistol primers. I am using Hornady dies for this caliber. At first I decided I wanted to use the Lyman 311041 173 gr. flat point for a hunting boolit. I dont know why, but it just seemed like a good un. Cast of 50 / 50 WW/pure and air cooled, sized to .311 and checked with Hornady checks. Then lubed with LLA straight. I loaded my rounds over 17, 18, and 19 grains of Herc 2400. No crimp. Results were...... well about that at 25 yards. Around an inch and a half and very uneventful as far as power goes. But hey, ya gotta start somewhere, right?

My rifle chambered these rounds quite easily without putting any rifling marks on the front bands when crimped in the crimp groove, so I knew I hadn't filled the throat completely. My bore showed what appeared to be ash in the barrel and upon swabbing, I did not see what appeared to be lead, but unburned powder. So, I changed one thing first. No resizing the case necks. I hand seated the boolits then used a light crimp to hold the lead in the case. The crimp did not contact the boolit, just settled in the crimp groove. The boolit could still easily be turned by hand but would not move forward or back.

Back to the range. At 25 yards, these next set of the same powder charges yielded groups about a quarter inch smaller than the time before. Getting Better! Bore still showed signs of ashing. Now although the groups shrunk, the groups moved about 2 inches left and 2 inches low. Quick adjustment to the scope and back to the gun room. Again, no lead, just unburned powder coming out. So, I decided to up the game to a Winchester large rifle primer.

So now we are up to unsized cases, Lyman 311041's, 17, 18, and 19 grains of 2400 powder and Winchester large rifle primers shooting 5 shot groups at 25 yards. Back to the range. Groups shrank evenly to under an inch at 25 yards. Better, but not great. Checking the bore, I had less unburned powder, but something just wasnt right. I decided to change lubes to 45/45/10.

Unsized cases, lyman 311041's, 17, 18, and 19 grains of 2400, Winchester large rifle primer, but now I am going to shoot 5 shot groups at 50 yards. At 50 yards, I started getting just over an inch groups. Bore was bright and shiney. At this point, I decided not to clean between range trips. But the charges were still slow and I was worried about not creating enough energy to RELIABLY take hogs out to 200 yards. I decided to increase my charges.

Now, I know it is the wrong thing to do, but this time I used two variables. Since 19 grains of powder were giving me the best groups, I decided to load 45 rounds. 5 with the 311041 over 20, 21, 22 grains of 2400 for 15 rounds. 5 each of the Lyman 311466 with the same charges, and the Lyman 311291 DW. Now this is where things really start tightening up. 21 grains of powder under 311041 gave about a 3/4 inch group. All the loverin style 311466 shot...... well, not so good. But the 311291 really showed promise. But only at 20 grains powder. To shrink groups at 100 and at higher charges, I decided to water quench some boolits.

All the same as above, but with water quenched boolits. Now I know water quenched boolits dont really expand on flesh, but since Scott was nice enough to give me a copy of Beartooth Bullets Technical Guide, I learned it is possible to softpoint water quenched boolits. Since I am only shooting paper, I am not softpointing these. Moving to 100 yards, Groups Improved!!! At 100 yards, the 311041 shot into 1 1/2 inches at 21 grains at 100 yards. The 311466 loverin shot into 2 inches at 100 yards at best. The 311291 DW shot into 1.07 inches for 5 shots at 100 yards with 22 grains powder!!!!!!! Recoil was brisk, and I had lots of confidence in this design and load.

Now I dont think that this will exactly cycle the action of an M1-Garand, but I cant wait to try it out in my bolt gun. I have loaded 15 of the 311291 softpointed and loaded as before. I also loaded 5 seated to the second band and another 5 at the third band. Now none of these had any problems chambering, so I have high hopes.

Stay tuned!!!

[mpmarty]

Heck in my 30/284 Winchester I use 25gr of 2400 with a LP primer and have no unburned powder and accuracy is 1" at a hundred yards with 3 of five touching. Boolit is a 31141 flat nose lubed with 45/45/10 and no gas checks.

My scope on my Savage is the Chinese copy of your Leupold. 4.5X14X50 side focus and mil dot.

[Wolfer]

101
Good read. A lot of it sounds really familiar. About a month ago I acquired a 311-041 and dedicated my old 760 to cast. I've put a lot of deer on the ground with this old gun but with full power loads it kicks like a bay mule.
I started with 2400 because I've had such good luck in my 8 mm Mauser. The 06 seemed to work best at 20 grains for about 1720 fps with my alloy at 9/10. I can't seem to push this alloy any faster than this. Today after work I loaded some water dropped ( bhn 14 ) and instead of 2400 I used Ramshot Exterminator. Dark was coming on fast so I didn't get to play much.
Keep in mind this is a 53 model gun and a 4x weaver scope
28 gr ext got me 1750 and about an inch
30 gr got 1820 and about an inch and a half
32 gr got 1923 and around two inch
When I first set up I shot five of the 2400@20 grs which made a 2" group centered around the bullseye. Keep in mind these bullets were pretty much all behind the crosshairs .
It seems like on the weekends either the winds blowing or I have something to do so it's taking me a long time to wring this out. I believe the Exterminator is showing a lot of promise although I would be pretty comfortable hunting with the 2400 @ 20 gr load
Keep us posted

[curator]

18 grains of 2400 or 25 grains of Wc680 and #314299 and you wil have 1 1/2" groups at 100 yards if you have good sights or scope. Size to .311 and neck size with no crimp.

[Boerrancher]

Trey,

It is great that you are getting your '06 to shoot cast really well. My 03A3 is a so so cast shooter, but it is all original military. One thing I learned with my 30-30 and my '06 is to not be afraid to try some of the faster rifle powders like IMR3031, through IMR4064. I have found that some of my best cast groups have been shot with 3031 powder @ 100 yards. Once you find your load with the pistol powders that shoots good, and you know your boolit size and lube are right, then if you so choose to progress to the rifle powders you can. I learned long ago to get a gun shooting good with pistol powders before moving on to rifle powders. It looks like you are most of the way there.

Best wishes,

Joe

[x101airborne]

Thank you, Joe. This is my first attempt to get MOA or under from a center fire bottleneck rifle. I plan on running this from pistol powders to 20mm vulcan powder. What I would like to see is a 180gr plus running around 2500 fps. Realistic? maybe not. But..... It COULD happen.

I know this may not be such a stretch for some of the more seasoned casters, but I am proud. It took over 4 days at the range to get here. And I plan on taking it to the max. The next project will be the 6.5x55!

[runfiverun]

don't be afraid to try some fillers [dacron] in those loads.
from 2400 on up through the medium rifle powders it will help with ignition consistency.
just remember to make sure it is under slight compression from the boolit.

[geargnasher]

Looks like you're getting it figured out, the .30-'06 is a fabulous learning platform for cast boolits. Starting with 2400 or even Unique is a good way to go, but once you get much over the limits of what 2400 will deliver, you might find you need to switch to a conventional lube, but only you and your gun will be able to tell you exactly where that point will be.

I get a pretty consistent 1.5 MOA at 100 with the Lee 312-185 sized .311", lubed with Felix lube, and pushed to 2,030 fps with 40 grains of H4350. It's a mild shooting fairly accurate load using water-quenched 50/50 wheel weights/roofing lead at about 17 bhn. I have things that shoot much better, but require harder boolits. The reason I only load to 2K fps is because the groups start to open up pretty quickly with this combo as I approach 2100, even with powders as slow as Reloder22. The common denominator is both pressure and velocity with four different powders. 24,000-ish (estimated) PSI and about 2,050 fps is the ceiling.

Now, with 28 bhn boolits it will do 1.5 MOA right up to about 2400 fps with a 311299 before it falls apart, but that's a load for things that don't bleed when shot.

With paper-patched 160-grain ACWW boolits it shoots consistent 1-3/4" groups at 100, but at nearly 2700 fps! Sure wouldn't be afraid to hunt with that one.

Keep up the good work, and don't be skeered to step down in burn rate.

Gear

[35 Whelen]

I'm not surprised with your results using the 311291. I've had a hard time finding a rifle that WON'T shoot these bullets. Regarding the 31141, I worked up a load for deer in my issue 1903A3 that consisted of 24 grs. of 2400 and the 31141 cast of ACWW's seated the bullets to the rifling.
The load grouped under 2" @ 100 with the issue sights and chrono'ed 2005 fps. After 6-8 shots I'd have a light haze of leading in the barrel, but that's OK. I figure if I have to fire more than 10 shots in one hunting trip, then a little leading is the least of my concerns!
Keep us posted!

35W

[Wolfer]

Heck in my 30/284 Winchester I use 25gr of 2400 with a LP primer and have no unburned powder and accuracy is 1" at a hundred yards with 3 of five touching. Boolit is a 31141 flat nose lubed with 45/45/10 and no gas checks.

My scope on my Savage is the Chinese copy of your Leupold. 4.5X14X50 side focus and mil dot.

A couple of questions
How hard is your boolit/ whats your alloy?
What exactly is 45/45/10

[x101airborne]

I had the same questions. I know 45/45/10 is 45 percent Lee liquid Alox / 45 percent Johnsons paste wax and 10 percent mineral spirits.

I am not very educated, so I will not second guess anyone. But if it was easy to shoot a 30 cal boolit of any hardness to the velocity and pressures generated by 25 grains of 2400 without a gas check, there would probably not be any need for gas checks. Any boolit hard enough to stand up to that pressure is not going expand on flesh. My alloy is coming out at 13.5 bhn and expands quite well. But like I said, I have a lot to learn.

[geargnasher]

Pretty good observation, x101airborne. The other key is accuracy. It's quite possible to push un-checked or PB .30 caliber boolits to 2K fps with no leading, but accuracy fails very quickly much above 1500-1600 fps unless the alloy is ridiculously hard.

You'll know right away when you've exceeded the limits of your components when your groups start to blow up. Back off on the powder and watch the groups return. Sometimes I've worked loads up and down several times under different weather conditions to observe the "zone" that maintains best accuracy most of the time. Regardless of velocity as long as it's acceptable for the intended task of the load, when I settle on a load it's based on the most accurate combo. You'll only get that from lots of shooting.

Gear

[dodgyrog]

I've shot some 31141 (NOE mould) out of my 30-06 with 43gr Accurate 2046 giving around 2200fps. I got a 3" group at 110 yards. I'm hoping to improve on that.
The gun is a CZ with a Wilson 1 in 10" twist stainless barrel.
No leading using Carnauba Red lube.

[x101airborne]

That's cool. Ya gotta start somewhere. After trying the different seating or OAL lengths I plan on staying with this load for hunting while I play again with the 31141 but several other designs and powders. I was really surprised that rifle primers gave better results without filler. I mean, I had no knowledge to form an opinion before starting, but they REALLY made a difference. Like I said I plan on basically running the same tests with other powders probably using a couple in the fast rifle level, then mid rifle level, slow rifle level, then eventually moving to duplex loading with 50 bmg and 20mm vullcan powders. But that is a LONG way away. Even if I shoot as much as I would like, I doubt it would happen this year. And hopefully it may never get that far if I find a power load for hunting that will do around an inch consistently.

[Char-Gar]

A good rifle, 30-06 or otherwise will deliver accuracy with cast equal to what it will with jacketed ammo. This is based on 50 years experience with the round.

I have never been able to get optimum accuracy much past 17 or 18 grains of 2400. 15 or 16 most often will do much better. If you want to go past 1,700 fps or so it is time to leave 2400 on the shelf and go with a slower powder. There is a reason for this, but I will spare you the long lecture.

I shoot nothing but cast for many years now, simply because of the challenge. I got bored with jacketed bullets so went to cast, where there are so many more variables. Lots of fun, if you have a high tolerance for ambiguity.

[trixter]

I have been casting pure ww for my 45ACP and loving the results. I have a 228gr RN Lee 6 holer and a 230gr SWC Lee 6 holer. They have both worked flawlessly. Now I am getting ready to cast for my sporterized O3A3, and my bolt action 300 Savage, I am going to slug the barrels of both guns and hope I can shoot the same size boolit in both of them. I have a 2 hole Lee 150 gr RF, that I hope will work. It drops boolits at .3105 very consistently. I just want to be sure, then I can start shooting the rifles. I plan to start with Bullseye powder and large pistol primers. I am just starting to do the research on how much powder to use. Any pointers would be appreciated. I know there are a lot of other powders that will work, but this is what I have.

[x101airborne]

Trixter - If that is what you got, that is what you got. For bullseye powder, I would stay with subsonic plinker loads without gas check. See if you can load em over about 5 grains BE without a crimp as cast. If you have enough neck tension, probably will be one heck of a squirrel load. Past that, I am not of much help.

Char gar - If you dont mind, I would like the lecture. I would like to understand more about what I am doing and why it may or may not work.

[Char-Gar]

It isn't always the amount of the pressure, but how fast the pressure is applied to the bullet base. To much fast powder will impact the bullet base and can cause distortion of the bullet. The same amount of pressure released slowly down the barrel won't cause the distortion, or at least not near as much.

This is why fast powders start to lose their accuracy potential past a certain point. From that pressure/velocity point a slower powder will do less damage to the bullet.

Of course bullet temper, size and lubrication are all factors that play into this. A harder bullet will take a harder faster hit, than a softer bullets and live to tell the story.

There are balances in this cast bullet shooting business, but as a general rule, when you move past about 1.7K fps with 2400 and the like, it is time to go to a slower powder.

When trying for best accuracy, I find a load that will deliver the accuracy I want. In a 30-06 that would be ACWW and about 16/2400. The bullet will have to be a good fit to the barrel throat and rifling style. You need a good lube and most often a size of .310 or .311 will do best.

Once you have a load that is doing well, I can then try changing things, one variable at a time, so I know what is causing the change up or down. I will play with the powder charge looking for the sweet spot. Then I might change the alloy a little, If things hold out I might change the sizing diameter I might try a different primer. You need a linear approach to this, or else it will be a hit or miss proposition and if you hit a good load you will not know why if you start changing severeal variables at once.

It is possible to get 2.5K fps with good accuracy, but there is not much "slip and slide" in how you get there. You will find, in general..note the word general...

1. You will need a harder alloy
2. You will need a smaller bullet
3. You will need a slower powder
4. You will be the best lube available
5. Greater care in the mechanics of reloading will become important

[x101airborne]

Well, I ordered the redding type S neck bushing die to control my neck tension better, so I think that is a step forward.

What is generally accepted as one of the best lubes for high velocity rifle? I know opinions may vary, but what is yours?

[Char-Gar]

I have been casting pure ww for my 45ACP and loving the results. I have a 228gr RN Lee 6 holer and a 230gr SWC Lee 6 holer. They have both worked flawlessly. Now I am getting ready to cast for my sporterized O3A3, and my bolt action 300 Savage, I am going to slug the barrels of both guns and hope I can shoot the same size boolit in both of them. I have a 2 hole Lee 150 gr RF, that I hope will work. It drops boolits at .3105 very consistently. I just want to be sure, then I can start shooting the rifles. I plan to start with Bullseye powder and large pistol primers. I am just starting to do the research on how much powder to use. Any pointers would be appreciated. I know there are a lot of other powders that will work, but this is what I have.

I would not use Bulleye powder for cast bullet loads in rifles.That stuff is so fast that small increases in charge weight will result in a big increase in pressure. It will be very easy to cross from good pressure to bad pressure. The faster powder I would go to would be Unique, but I still would prefer 2400, 4227 or 4759.

I know it is tempting to stay with BE for the economy, but it really is a poor choice for you to start with.

[Char-Gar]

Well, I ordered the redding type S neck bushing die to control my neck tension better, so I think that is a step forward.

What is generally accepted as one of the best lubes for high velocity rifle? I know opinions may vary, but what is yours?

I have used my own mix of beeswax and Vaseline for over 50 years in rifles and pistols with great results. When I load above 2K fps, which isn't often, I use Felix Lube. I am certain there are others than work just as well, but that is what I use and it works fine.

I have not had good experience will Lee LA tumble lube. It has it's purposes, but they are somewhat narrow in scope. I just use my old stand by or Felix, and that way I know the problem is not with the lube, if a problem crops up.

I have never used a bushing die of any make, but their use should be a postive step.

[geargnasher]

As far as neck sizing goes, I use Lee Collet dies if at all possible during load workup because they are infinitely adjustable (though not supposed to be) and I can get the exact neck tension I want. Once I a certain OD established with a batch of brass, I can use the neck bushing sizer, but I find myself just using the collet die for everything I can because it works so well. If you change brass lots, boolit size, hardness, paper patch, etc. your neck OD size will most likely change some, and the Lee die allows you to do this on the spot without changing parts or buying a dozen different bushings.

I've shot everything from Red Dot to WC872 in .30-'06 with boolits from 100-grains to 220 and still learn something every time I go to the range with one. If you get outside the Lyman "box" of only loading shotgun powders behind cast boolits at low velocities, you'll be surprised what can be done. You might also be surprised by what doesn't work sometimes, too.

But like Char-Gar explained, the more slowly you can accelerate (launch) a cast boolit, the better. Gentle acceleration is best at any velocity as long as the peak pressure is sufficient for full combustion. So if I can get 1600 fps with a 180-grain boolit out of either 2400 or Reloder 7, I'm going with the Reloder 7 because Professor Target has told me that it's a better choice. 2400 might do better at 1500 fps with a 165-grain boolit. 4831 is a poor choice for 1600 fps and 180-grain boolits because it won't make enough pressure to burn consistently at that velocity. There's a range for every powder, spend some time studying reloading pressure data, boolit weight, and velocity, it's very easy to spot the trends. I'll bring a couple books with me next month that might help.

Oh, and for high speed lube, I swear by Felix lube, but have used various NRA 50/50 lubes with decent success, as well as LBT Soft and Speed Green. White label BAC or 2500+ is also a good choice, and if I were to buy it, would be my first choice. Larry Gibson will be along shortly to tell you that Javelina Alox is all you need, and I won't argue much with that either.

Gear

[Char-Gar]

I have had good luck with Javelina 50/50 also and if I were to buy lube that is what I would buy, because it is cheap and it works.

Some years back, a couple of members of this board did a "big melt" of Felix lube for all of us. Many of us chipped in and let them do the "double, double toil and trouble" stuff so we would not have too. I bought enough to last me a lifetime, no more than I use it. I keep one Lyman 450 machine filled with it and use it when needed.

It think the "big melt" was a true PITA as nobody has volunteered to repeat the experience.

[pdawg_shooter]

I use the Lee 170gr FP cast from AAWW. Size them .3015 and patch them back up to .312. Load them in un-sized brass over 57.0gr of AA4530 and a CCI 200 primer. I crimp with a Lee FCD. These will group slightly better than the same load with 180gr jacketed, but a bit higher.

[Larry Gibson]

X101airborne

Myself and numerous others have worked bullets such as 311291, 311041 and several other cast bullets of the bore riding nose design every which way at higher velocity. Normally best accuracy comes in the 1700 – 1900 fps range as reported. That is within the RPM threshold for the 10” twist. You may or may not believe there is an RPM threshold but it’s what’s giving you larger groups as you increase the velocity and RPM above 1950 fps. Working different alloys, powders, sizing, GCs and lubes I was able to maintain 2 – 3 moa at 2200 – 2300 fps with the 311291 for consistent 10 shot groups at 100 yards. If you want to improve on that accuracy at or perhaps a little higher velocity I suggest you change bullet designs and pay particular attention to minute details when casting and loading.

Bullet; with the ’06 the ideal cast bullet design is one that has minimal lube groove depth with enough lube for the length of barrel. It should have a short nose with minimal ogive of not more than caliber length. The bullet should have a bearing length from the beginning of the ogive to the base of the GC. That bearing length should just fit within from the base of the cartridge neck to the beginning of the leade. Two designs fill those requirements in most ’06 chambers; the Lyman Lovern design 311466 and the LBT 150 gr. With either bullet design moa accuracy with 3 -5 shots is obtained with proper casting, sizing and loading in the 2200 – 2300 fps range if the rifle/shooter are capable with a 10” twist rifle. With either cast bullet such accuracy (1 – 1.5 moa w/10 shot groups) can be obtained at 2400 – 2500 fps with a 12” twist and 2600 - 2700+ fps is possible with a 14” twist.

Alloy; I’ve found a strong yet malleable alloy of 18 – 22 BHN to work best. A hard brittle alloy with a high antimony content should be avoided.

Cast bullets; they should be visually inspected under a magnifying glass for any defects. If using a multiple cavity mould they should be weight sorted if they do not weigh the same from each cavity.

Gas Checks; bullet bases must be square and flat. If the sprue cut of is not even with the bullet base cut a sharp knife can cut it flat. GCs need to be soft so annealing them may be necessary if they are commercial. I use my own made from .015 brass shim stock. The GC should be a tight slip fit on the bullet shank. It should not be forced on and swage the flat bottom of the shank. A GC seater (I use the Lyman on a 450 with a .311 H die) should be used to squarely seat the GC and crimp before sizing. I then Push size the bullets through a Lee .311 sizer after a light spray of Dillon case lube. Only then are the bullets lubed in a .311 H die in the 450.

Bullet lubes; I’ve run multiple tests at HV with various commercial lubes. I consistently get the best accuracy with Javelina lube followed by 2500+. At high velocity/RPM the bullet lube needs to spin off very quickly and completely. Hard lubes do not and small chunks of lube sticking to one side of a cast bullet will unbalance it with inaccuracy being the result. Softer lubes work best at HV and I’ve yet to find one that betters Javelina.

Cases; should be “match prepped”, well fire formed, neck sized with .002 neck tension, with uniform neck thickness.

Powders; I’ve had best results with AA4350, RL19 and H4831SC. If loading density is below 80% I use a dacron filler.

Primers; I’ve also ran numerous tests with different primers. “Soft” primers will lower velocity and RPM with these slower burning powders. Accuracy will appear to be better but it is the lower velocity/RPM from such. Load all to the same velocity/RPM and it’s hard to pick a “best” primer. I mostly use WLRs because that’s what I buy in bulk. Magnum level primers are not needed in the ’06 with these powders and give higher SD/ESs which isn’t good for accuracy.

There you have my advise based on “been there, done that” numerous times. My best advise if you want jacketed bullet accuracy at jacketed bullet velocity in and ’06 is to get a quality 14” twist barrel 26”+ long and follow the advice I’ve given. You will be amazed at how easy accuracy at HV then comes with cast bullets, even with 311291 and 311041.

Larry Gibson

[Char-Gar]

Years ago I had an 03 Springfield barreled by Joe Phifer with a barrel of his own make. It was a 1-14 twist 30-06 with a length and contour almost identical to the arsenal barrel. I used good old 311467 and depending on the powder, it was no trick to run those 2.5K fps.

One of the quickest ways to get a heated argment going here is to float the idea of an max RPMs. I run when those start as I am not a tech guy. But my experience with the 1-14 Phifer 30-06 tends to make me think such notions are indeed valid.

[youngda9]

Don't full length size if you want accurady. Neck size only...and only about 3/4 of the neck.

[tonyjones]

Gear,

When using the Lee collet die do you vary the size (diameter) of the mandrel to control for neck tension as well as bullet/chamber neck/loaded cartridge neck diameters? Do you make/alter your mandrels or buy them? Where/from whom do you buy them if that's the case?

Thanks,

Tony

[Char-Gar]

Don't full length size if you want accurady. Neck size only...and only about 3/4 of the neck.

Don't tell that to a match shooter! Sterling accuracy can be had in MI Garands, M1As, Ars and other rifles with flull length sized cases.

For neck sized only cases to truly shine in the accuracy department, you must have a dead straight and round chamber. In the run of the mill sporter and military rifle there will be little, if any increase in accuracy for NS cases.

Neck sizing can be one piece of the accuracy puzzle, but it is far from the whole game. MOA accuracy can be had with FL sized cases if everything else is correct.

[DLCTEX]

You can back off the Lee collet die to size the case neck less.

[Wolfer]

X101airborne
I don't know about you but I'm learning a lot here and it's much appreciated

[x101airborne]

X101airborne
I don't know about you but I'm learning a lot here and it's much appreciated

Lemme tell ya. Whe people like Larry Gibson, Char Gar, Gearnasher, and a whole lot others start talking, my output becomes a lot less and my ears get bigger. One thing I have learned from them in the short time I have been here is...... they do their best to get me to water, it is up to me to drink.

[x101airborne]

One of the quickest ways to get a heated argment going here is to float the idea of an max RPMs. I run when those start as I am not a tech guy. But my experience with the 1-14 Phifer 30-06 tends to make me think such notions are indeed valid.

Man, you arent kidding. Hence the ONLY person on my ignore list. I have never seen anything start a fight quicker other than saying "Your kids are uglier than mine" or "Your beer is more skunky than mine".

Everything about max RPM's makes sense. Hence why PALMA shooters match their twist rates to the bullets they are shooting and the range and the speed. Unfortunately, without spending a couple C-notes on a barrel, I have not seen anything lately that is anything other than 1-10 twist for 30 cal. While I would like to do all I can, I want to do it with what I have now. I just wish I had a 1-14 barrel!

[mpmarty]

Tomorrow I go to the big range where I can shoot 100 or 200 yards. I'm using a very accurate K-31 with diopter sights and am shooting LEEs copy of the 31141 a 170gr flat point without gas checks. Loaded up 50 with RL-7 and another 50 with 23gr of 2400. All with Wolf LP primers. Cases are all WW .284 Winchester necked up to 30cal so in effect I'm shooting a 30/284 wildcat. Case capacity is almost the same as 30:06 I had to go to 23gr of 2400 to get complete combustion. Lube is 45/45/10 and so far no leading in this pristine barrel.

My stock of 2400 is old from the sixties and seventies so may be "slower" than current production.

[x101airborne]

Very interested to hear your results. Thank you for sharing. What is your alloy? Do you neck size? Do you load without sizing your cases? I am interested to hear more.

[geargnasher]

Tonyjones: I don't change mandrels, it isn't necessary unless you have a truly minimum, match-grade chamber and are using fireformed brass from that chamber. Even after multiple partial collet-sizings (i.e. NOT sized until the neck ID touches the mandrel) the necks remain concentric. I turn down the die until it swages the neck to the ID I desire to give me the boolit tension I need.

x101airborne, You might want to print out Larry's post #25 and staple it to the wall of your reloading shack, it is the most complete and concise cast boolit guide for pretty much any bottleneck 30-caliber that I've seen in a while.

Pay particular attention to what he said about sizing the boolits. It's important to seat the gas checks squarely, annealing Hornady crimp-on checks is a good idea because they seat more concentric and damage the boolit less, and lubing with any kind of case lube and nose-first sizing them keeps the nose, bands, and check all in a nice line. Just use your lube-sizer to apply lube. Pre-sizing the boolits this way takes the stress off of the boolit nose when lubing in a base-first sizer, and since none of the base-first sizer rams are perfectly in line with the sizer bore and they all have some degree of slop, taking the pressure off the nose helps keep it from getting bent when you shove them down the hole. Another trick is to let the top punch "float", just roll a little ball of boolit lube and stick it in the hole before you insert the top punch, let that lube retain the punch and remove the set screw. If you cast your boolits, check them, and push-through size them, then wait about a month before using the base-first sizer to lube them, all the better.

Alloy. I couldn't have said it better. For serious loads, more than 1600 fps, a tough, malleable alloy made from water-quenched or oven heat-treated 50/50 clip-on wheel weights and pure lead with about 1% tin or a shade more added to the total is really tough to beat, and will mushroom very, very nicely at 1800-2200 fps. The trick is it takes quite a while for it to get hard enough to shoot, so cast bunches when you do so you don't run out in the middle of some intense testing (which can take many hundreds of boolits sometimes). I started using this alloy after getting immersed in several of the RPM debates in the past couple of years, it has made a world of difference in the way my "regular" cast boolit loads shoot.

Getting lube to jettison completely right at muzzle exit is a very important key to fine accuracy. Once I had a load that just wouldn't group tightly on a cool day, and noticed little flecks of lube stuck to the target, at 100 yards. Some of the lube was coming off at the muzzle, and some was flying off in chunks all the way to the target like mud slinging from tires when you get back on pavement. I went back to the bench, melted the lube, added some ATF to it, hand lubed a few, went back to the range and voila', no lube on the target and tight groups. Gained about 40 fps too, and the chrony was spattered with lube at 12 feet. Since then, I do the "spatter test" on any lube I try, and do it at a multitude of ambient temperatures and barrel temperatures to make certain it's consistent. Basically, I shoot through a large piece of cardboard at 10 feet from the muzzle and observe the lube pattern, then shoot at 25 yards and if there is any lube on the target backer, I reformulate the lube. I like Felix lube because simply adding or subtracting lanolin, carnauba, or the mixed oils will control lube jettison and maintain proper barrel lubricity so I get no lube "Klingons" and no purge flyers, either.

One thing Larry didn't mention that can, in some situations, be very important to accuracy is chamber neck clearance. Most production chambers are a bit large and don't allow a tight fit unless you use an excessively large boolit. By tight fit I mean 1.5 thousandths total clearance. It goes along with what Larry said about boolit shape. You want a short nose that has a minimum of unsupported length so it won't slump upon firing and possibly ruin balance, and you want it to reach from the base of the case neck to the leade and touch everything in between, in other words be fully supported by the case, throat, leade, etc. If the case neck isn't supported by the chamber neck, all this is moot. The boolit MUST start straight to have any hope of being accurate. You need some clearance for safety and for the boolit to be released from the case neck with minimal damage on firing, but too much clearance will get the boolit started lopsided into the bore, which can distort the boolits geometry and make it wobble in flight, opening groups. How much this matters is up to you to mess with and eliminate, and depends a lot on the chamber you have to work with, the boolit size the gun likes, and the thickness of the case necks you have to work with as well.

One of these days I'm going to get a twelve-twist .30-'06 so I can fling 311299s at a decent speed with more reliability, less fuss, and much better game-compatible alloy than is possible with my current barrels. Larry has proven that it's easier to extend the accurate velocity window many times over and in great detail by slowing the twist using fairly conventional (but very precise) loading techniques, I can't wait to try it myself.

Gear

[MikeS]

After reading this thread I have a few questions. First off, I see that some people started their load development using pistol primers, rather than rifle primers. What is the purpose of doing this? I was under the impression that pistol primers used a softer metal, and that when hit by a rifle's firing pin could rupture, causing gas to escape in ways it wasn't meant to! The next question is why would anyone want to use unsized cases, but crimp the boolit in place? I can understand neck sizing the brass to hold the boolits without a crimp, but it doesn't make sense to me to have the boolit so loose in the cartridge. When neck sizing, wouldn't that really only be a benefit if the cartridge casing is indexed to the chamber, so it's always sitting in the chamber the way it was when it was originally fireformed? If that's the case, then wouldn't neck sizing only really work better than FL sizing if the cartridges are fed into the rifle one at a time (not from a magazine)?

I'm not a target shooter as in a benchrest, or other high precision type shooting, and the only 30 caliber rifles I have are a 16" barreled Win 94, and a Ruger Mini-30, and neither of these rifles are known for their accuracy, and both action types are ones that most people say need full length resizing, so is neck only sizing out of the question for these rifles? I'm also not a hunter, so really the only use these rifles will get is plinking style 'target' shooting, and possibly (although I hope it never happens) home defense type shooting, so am I better off to always full length resize to make sure they feed reliably from their magazines? Thanks!

[Wolfer]

Mike
I can't help you on your first questions but I can tell you I started reloading in the early 70s with
a lee loader ( mallet type ) for my Marlin 30-30. I ran a truckload of neck sized brass through that gun with never a hitch that I recall.
That being said I do full length size all my brass now.

[x101airborne]

Good morning, Mike.

I cant speak for others, but I can tell you why I did some of the things I did.

At the pressures generated in the case capacity of the 06, I was not worried about unexpected pressure leakage. And I heard that pistol primers CAN change pressure curves and can make a difference in accuracy. It was one of the variables I wanted to rule out early.

As far as using unsized cases, I tried them so they were a tighter fit in my chamber. I especially wanted my necks to sit centered in the chamber. And since my standard die resized my case necks down too tight, I didnt want to use it. But my chamber is loose enough to allow the boolit to slip in and out of the case without restriction. When I decided to crimp my boolits in place, I dont actually crimp into the boolit. I crimp into one of the grooves. The boolit is still loose and unsized, yet unable to move forward or back during recoil or handling. Until my redding neck sizer gets here, it is the best I can figure out.

[mpmarty]

Very interested to hear your results. Thank you for sharing. What is your alloy? Do you neck size? Do you load without sizing your cases? I am interested to hear more.

Alloy is ACWW. I full length size in Redding die. Boolits are tumble lubed in 45/45/10 and not sized or checked. I have to force the cartridge into the chamber as the nose is engraved by the rifling for most of its exposed length. I'm careful to seat my primers below flush to avoid slamfires. I'll post results here this evening after the party.

added: I use a LEE factory collet crimp die on all these rounds even though there is adequate neck tension.

[Larry Gibson]

Mike

With most cast bullet loads neck sizing is the way to go with the 30-30 in a M94. That's what I do for mine. I use an RCBS X-die to FL size when necessary for the M94s. The X die is also used for loads in the Contender Carbine to prevent FTF as it is sensitive to locking.

With loads that function the Mini30 action you'll probably have to FL size, not sure as I've not loaded expressly for the Mini30. I have loaded lots of cast bullet and jacketed bullet loads for use in SKS and AK rifles and they require FL sizing with most any load that functions the action but with some you can get away with one or 2 firing with jus NSing. However, concerns of OOB firing cause me not to do that. With just one rifle to feed adjust your FL die so sizing is just enough to allow the bolt to close with no resistance. This, in effect, adjusts the cartridge headspace to your Mini30 chamber and case life will be long while trimming less often. I trim the cases every 4-5 firings.

BTW; my standard cast bullet load for the SKS/AK is the C312-155 (Cast of WW=2% tin, sized .312 with GC and Javelina lube) over 27 gr 4895 in WW or IMI cases with LR primers. Runs 1850 - 1900 fps in most 20" barrels and gives 100% reliable functioning in SKS/AK rifles and the few Mini30s I've tried it in and with accuracy as good as it gets with those rifles.

Larry Gibson

[mpmarty]

OK it was a great day weather wise, toasty warm 58 degrees and NO WIND.\
The labels say it all. 23gr 2400 was clearly the best of the two.

[geargnasher]

See? It all depends on YOUR gun, YOUR tools, and YOUR techniques! I had exactly the opposite results with those two powders in the '06, with two different boolits.

Gear

[9.3X62AL]

Lots of fun, if you have a high tolerance for ambiguity.

Charles, you summed up the cast boolit experience in one sentence, right there. THIS NEEDS TO BE A STICKY, PERHAPS THE BOARD'S MOTTO!

[MikeS]

Mike

With most cast bullet loads neck sizing is the way to go with the 30-30 in a M94. That's what I do for mine. I use an RCBS X-die to FL size when necessary for the M94s. The X die is also used for loads in the Contender Carbine to prevent FTF as it is sensitive to locking.

I see you're using an RCBS X die, how do you like it? Do you find that it really makes a difference in cases not needing to be trimmed, other than the initial trim when first using the brass?


BTW; my standard cast bullet load for the SKS/AK is the C312-155 (Cast of WW=2% tin, sized .312 with GC and Javelina lube) over 27 gr 4895 in WW or IMI cases with LR primers. Runs 1850 - 1900 fps in most 20" barrels and gives 100% reliable functioning in SKS/AK rifles and the few Mini30s I've tried it in and with accuracy as good as it gets with those rifles.

Larry Gibson

I have that boolit, along with it's TL brother. I cast them with Lyman #2 alloy, sized them to .311 (when I slugged my Mini-30 it came out at .3095) and I loaded it with 16gr of 2400. I haven't gotten the Mini-30 to the range yet to test it. Are you using IMR or H4895? Bass Pro Shops has both powders in stock, is there any benefit to one or the other? I'm not totally sure, but I seem to remember that one was about $4.00/pound more expensive than the other. Thanks!

[x101airborne]

MPMarty, Those are some excellent results. Man if I could get away with no checks, that would save a lot of time.

[x101airborne]

Wife and I just shot these loads at a 10 inch steel pipe cover at about 200 yards. She was having so much fun!! To hear the ring and see the smoke was a real kick for her. I wish I would have brought more ammo.

[Larry Gibson]

MikeS

I see you're using an RCBS X die, how do you like it? Do you find that it really makes a difference in cases not needing to be trimmed, other than the initial trim when first using the brass?

I really do like the RCBS X-die and have several of them for different cartridges. With the X Die I reall y do no longer have to trim. With some cartridge (mostly for the ammo used in milsurps) I do not even do the 1st trim as per the instructions if the cases are once fired or new.

I have 1500+ 7.62 NATO cases that had been loaded with regualr FL dies and fired 4-5 times in my M1As They were in the 'throw away bucket as another firing would have resulted in case head seperations. I sized them all with the X die and use them in my FR8 bolt gun and they are now on their additional 3rd firing w/o a case head speration.

I gave and use the X die in .223, 22-250, 243, 6.5x55, 280, 30-30, .308W, 30-06 and 8x57 if that tells you how much I like and use them. I wish RCBS made them in all cartridges.

I have that boolit, along with it's TL brother. I cast them with Lyman #2 alloy, sized them to .311 (when I slugged my Mini-30 it came out at .3095) and I loaded it with 16gr of 2400. I haven't gotten the Mini-30 to the range yet to test it. Are you using IMR or H4895? Bass Pro Shops has both powders in stock, is there any benefit to one or the other? I'm not totally sure, but I seem to remember that one was about $4.00/pound more expensive than the other. Thanks!

I've used H4895 and 3 different lots of milsurp 4895 (2 were Dupont) in the 7.62x39 in gas guns and in my Mini MK X bolt gun. I prefer the H4895 because its smaller kernals give better loading density and it throws more accurately. I also modified the gas tube on my SKS to dampen the ejection cycle making it easier on the brass and easier to find them.

Larry Gibson

[MikeS]

I too have an X die set in 30-30, but I just got it recently, but haven't had the chance to shoot & reload any ammo sized with it which is why I asked about it. Good to know that it really works, and isn't just hype. Before I got the X set I used a Lee set. Now the set I use is like Alphbet cereal, first an X die, than an M die, then another X die (the seater) and then an FCD die! :) Thanks for the info!


---
I am here: http://maps.google.com/maps?ll=26.088742,-80.403768

[geargnasher]

MikeS, talk to me about the X seater die. I'm looking for a better "straightline" seating die that actually supports the case full length and guides the boolit into it for better concentricity, especially in .30-30 with the thin brass. Also looking for a die that will do this with .311" boolits and brass that hasn't been FL sized, so I don't want much from a standard production die, do I!

Gear

[Char-Gar]

Gear...The best seating die to do what you wish is (IMHO) the old fashion chamber type hand seatng die as made by L.W. Wilson. They will make you one in 30-30 with a .3125 bullet seating chamber for cast bullets. It is custom order, but their turn around time is quick and their price is the same as a standard seating die. At least the last one they made for me did.

Being cut to chamber dimensions, these will accept unsized cases just fine.

My 30-30 SL seating die is the same design, but I made it from the breech end of an old 30-30 barrel. I also made from from the stump of an old Krag barrel for the 30-40 round. My .308 was made by Wilson.

For the 30-06, I use a Vickerman with a custom .3125 seating chamber, but they don't support the case full length like a chamber type dies does. I had a decent 03 barrel I was going to use to make a chamber type hand seating die, but a friend talked me out of it, and a 8X57 barrel for which I had like plans.

The Vickerman works just fine, unless a fellow gets to wild about anealing his cases and soften the shoulders too much. I have a lot of old CIL (Canadian Industries Limited) 30-30 cases that are paper thin and must be handled with care. Years ago when CIL went under, Midway was selling these cases for half the price of US brass and I laid in a big supply. You can crumple the shoulders on these real easy, unless you go very slow and easy with the bullet seating and they have not been anealed.

I have been a big fan of straight line seating for many years. It is of course just one piece in the puzzle. The chamber of the rifle that produced the case must be at a true 90 degree angle with the bolt face, round and dead straight with the bore. All of this plus neck turning the case neck will give us ammo with minimum runout.

[geargnasher]

Thanks for the info Char-Gar. I'm sure you meant L.E. Wilson, not LW!

Last I remember Sinclair carried their product line.

Gear

[MikeS]

Actually I don't think there's any difference between the seating die that comes in the X die set, and a standard seater.

[excess650]

30-06, 7.5x55 (30-284) and 7.62x39, yep, I have 'em all in bolt guns. The real surpriise was my CZ 527 7.62x39. I bought it new and have never fired a single round of jacketed through it. My pet load is 23-25gr H322 in Lapua cases with WLR primers. The boolit of choice is a Lee C309-150F from an old SC that I have. They drop .3115"-.312", but I size and lube in a .313" die. Accuracy is better than if done in a .312" die. I use only lube ahead of the GC, and additional lube will open the groups. I have fired literally hunreds of rounds without cleaning, and see no reason to clean. The lube is some of my homebrew, but I like it better than LBT Blue or Blue Soft.

My alloy is "mystery metal" wheel weights, range lead, soft lead, and tin that drops around 12.-13.5 bhn but hardens to 16-18bhn when water dropped. It isn't brittle.

30-06 and 7.5x55 (K31) have near identical capacity. My '06 is scoped but both K31s wear receiver sights.

The "hot load" for the 1967 vintage Remington 700 is RP cases, F210M primers and 29gr AA5744 under the Saeco #301 (200gr in my alloy) sized and lubed in a .311" die. A couple of other loads showing promise are 30gr AA2015 and 29gr H322.

The K31 "carbine" is a cut down (20.5") K31 wearing a receiver sight and bead front. The barrel doesn't match the receiver serial #, and it shows no wear, so appears to be a new barrel. My boolit of choice is a new style Lyman 311644 S&L in a .311" die. The higher veloctiy loads that I've worked up were in PP cases using F210 primers. I took some (new) surplus 4895 from 30-40gr and found the sweet spots at 36.0 and 38.0gr. With H322 I started at 27 and went to 35, but found best, repeatable accuracy at 30gr (sub 1.5moa with irons suitable for woods hunting!)

My standard loads have used FL sized cases expanded with either a Lyman M die or tapered expander with just enough flare to cover the GC. I seat the boolits out so that they lightly engrave rifling when the bolt is closed. In that the K31 has little camming power, I prefer to not have more than 1/16" interference when closing the bolt. I do not crimp.

These loads have all been shot to at least 500m. I've shot the 30-06 all the way to 1000 yards, but have a tipped based (20moa) Burris Posi-align ring inserts +/- 5 min in 30mm, and a scope with in excess of 150 min elevation AND mildots. I need to work with my NOE 311299 and see how much flatter it will shoot than the Saeco provided it shoots as accurately.

[x101airborne]

Dang, that is good shooting.

[excess650]

Dang, that is good shooting.

Its only 3 shots, but with only 5x. I was just verifying my POI for deer season.

[Char-Gar]

Thanks for the info Char-Gar. I'm sure you meant L.E. Wilson, not LW!

Last I remember Sinclair carried their product line.

Gear

Yes...L.E. Wilson. The "E" and the "W" are right next to each other on most keyboards. Easy to hit the wrong one with fat fingers. These Wilson hand seaters come with bullet just .001 over nominal jacketed bullet size. The 30 cals are .309, and that is what Midway will stock. To get one .3125 you will have to go direct to Wilson. .3125 is the nearest reamer size to what we want, that Wilson has in their tool room.

The last time I ordered one, I just picked up the phone and called them. They made it and sent it out within 2 days along with the bill, which I promptly paid. Hard to find service like this any more.

[Larry Gibson]

Actually I don't think there's any difference between the seating die that comes in the X die set, and a standard seater.

There isn't any, it's the same seater. You can get the FL X die by itself if you've another set.

Larry Gibson

[Recluse]

x101,

I did some MOA experimenting with several cast boolits and ended up using a 200 gr boolit. Like you, my thoughts were for hunting, and so after many months of trial and error and discovery. . .

Alloys and their hardness/blend seemed to affect where I could push them, velocity-wise, and maintain accuracy, but there too was a Catch-22. The group below, for a 3-shot group, is within MOA for 100 yards, but the alloy blend has more lino in it than I would prefer and was water-quenched as well.

It made for an extremely hard boolit that would be of little use hunting smaller game, although maybe for larger pigs it would have no trouble punching through. But at the end of the day, while accuracy was good, I had no confidence in it as a hunting round.

http://castboolits.gunloads.com/picture.php?albumid=252&pictureid=4903

This was using an extremely hard alloy in a Hornady gas-checked Lee 200gr boolit sized to .309 and pushing it with 41 grains of IMR 4350 with a CCI Large Rifle primer and RP brass, full-length sized, third-firing of the brass. Lube is my own recipe.

My chrony broke several years ago and I simply have not replaced it, :oops: so I'm not sure of the velocity.

So now that I had a hard alloy I could keep in a reasonable group, I started experimenting with softer, more practical alloys--mainly wheelweight boolits that were air cooled or water dropped. I also tested my (new at the time) 45/45/10/beeswax hard lube.

I dropped down to 34 grains of IMR 4350 and here's what I got--

http://castboolits.gunloads.com/picture.php?albumid=252&pictureid=4915

This was a gas-checked Lee 300grRN boolit sized to .309 and using my new 45/45/10/beeswax lube. Again, I wish I could've chrony'd the rounds for velocity, but I'd be fairly comfortable taking this round into the field for hunting small deer and even small pig.

Next, I began upping the powder charge a bit. This next target was with 37gr of IMR 4350 with everything else being the same as the 34gr load. As you can see, the group spreads out a bit.

http://castboolits.gunloads.com/picture.php?albumid=252&pictureid=4914

Next, I go back to my boolits using my red lube and up the charge to 39 grains (IMR 4350) and again, the groups grow yet a bit larger. Still, for 100 yards and a lead boolit, I can live with this as I also know the velocity is increasing, thus giving me better knock down power for slightly larger game.

http://castboolits.gunloads.com/picture.php?albumid=252&pictureid=4916

And finally, at 42gr of IMR 4350, the group size stays about the same as with 39 grains.

http://castboolits.gunloads.com/picture.php?albumid=252&pictureid=4917

MY conclusions, and please feel free to educate me (please feel free :)) are that with a harder alloy such as the lino water-dropped boolit, I can push it faster and get good accuracy, but the effectiveness of the boolit (expansion, namely) is sacrificed greatly.

With softer alloy'd boolits, I can reduce the charge and get even better accuracy. I would suspect that game knockdown power would also be good due to the reduced velocity giving the softer alloy'd boolit a better chance to deform somewhat.

These are all "educated" guesses, so again, I'm very open to feedback.

But, the bottom line is that you CAN get MOA out of a 30-06 with cast boolits AND an effective hunting round if you work up the right combination of components.

I'm probably not going to do any more experimenting with cast boolits in the 30-06 for a while as I have an itch to work up some new loads for some new jacketed HPBT projectiles.

:coffee:

[Char-Gar]

There is hunting and there is target shooting and the two should not be confused. When shooting at targets the concern is bullet landing close to each other. In hunting, the concern is putting the bullet where we want it to go and killing the animal in a quck way so it can be recovered.

MOA is not needed for hunting. 2 MOA is all that is needed and most often less than 2 MOA is plenty good.

It is easy to get 2MOA at 1,700 to 1,900 fps from an ACWW bullet out of a good 30-06 and that is all that is needed.

If you truly feel you must have MOA out of your cast bullet hunting rifle, the cast from straight linotype and hollow point the bullets. The nose will shatter and blow off forming secondary missles and the base will continue on through the animal. It will act like a Nosler Partion. There will be some meat loss this way, but the animal will be grave yard dead.

[Larry Gibson]

MY conclusions, and please feel free to educate me (please feel free ) are that with a harder alloy such as the lino water-dropped boolit, I can push it faster and get good accuracy, but the effectiveness of the boolit (expansion, namely) is sacrificed greatly.

Such is the case, especially with hard bullets that are not brittle. The harder bullet can resist the adverse affects on it's balance during acceleration. However, any imbalance to a bullet at all will still be adversely affected in flight by RPM. The higher the RPM the greater the adverse affect and thus the greater the inaccuracy (group opens). At some point the adverse affect of the increased RPM will greatly impair the accuracy and that point will be the RPM threshold. The better balanced the bullet is going in the rifle and the better balanced we keep it during acceleration the higher the RPM threshold will be.

Excellent hunting accuracy can be had in the '06 with softer malleable alloys that expand well on game upward of 2000 fps but 1900 - 1950 fps in 10" twist barrels as Char-Gar mentions. I've found that an AC'd bullet such as yours cast of WW = 2% tin and then mixed with lead at 50/50 and HP'd with the Forster 1/8" HP tool to 1/8 - 3/16' depth gives excellent performance on deer, pigs, etc. to 200 yards. With such hunting loads I clean the barrel every 7 - 10 shots to maintain best accuracy. That's plenty of shots for hunting. I also suggest you test your selected load for accuracy at the maximum range you expect to use it. For me that is 200 yards where sufficient accuracy and velocity for expansion can still be expected. Using 3 and 4 shot groups at 100 yards are not statistically valid and may give a false impression of the real accuracy of the load. Also, if you are pushing the RPM threshold accuracy can be acceptable at 100 yards but, if over the RPM threshold group expansion will be non linear. Thus groups at longer range will be much larger than normally expected.

With softer alloy'd boolits, I can reduce the charge and get even better accuracy. I would suspect that game knockdown power would also be good due to the reduced velocity giving the softer alloy'd boolit a better chance to deform somewhat.

Exactly correct. Use the softer malleable alloy for bullets in the 1800-2000 fps range, HP them slightly with the Forster tool and you'll find cast bullets in the '06 are very effective to 200 yards on deer and pigs. However, you still have to put the bullet in the right place....sometimes the hardest part:grin:

These are all "educated" guesses, so again, I'm very open to feedback.

Not "guesses" at all, many, many of us have proven them as fact. You're definitely on the right track.

But, the bottom line is that you CAN get MOA out of a 30-06 with cast boolits AND an effective hunting round if you work up the right combination of components.

You have found your "What I would like to see is a 180gr plus running around 2500 fps" is perhaps unrealistic with a 10" twist '06 if you are expecting moa accuracy with such. However, you have found that with a moa capable 30-06 rifle moa accuracy is quite possible with cast bullets, just not at 2500 fps is all. Good luck hunting with that rifle BTW, you should be successful with it.:drinks:

Larry Gibson

[x101airborne]

The more I shoot it, the more I am gaining confidence in this boolit and alloy. It is an easy enough load that the wife likes shooting it. It does seem to have more of a "30-30" trajectory than what I am used to, but the point of this is education, so it is the game. The boolits are soft enough that if I drop the loaded shells, the boolits will deform, so if anything I think they are a little soft. I could probably water drop these and be able to do more velocity and still get some deformation on impact. Or, just switch over to straight WW's +2% tin for my rifle needs. And I still need to order some better lube, although I am fairly impressed with the 45/45/10 for standard velocity uses.

Yall should have seen how those lead booits were cratering that hardened steel plate. If they will do that to a steel 1" thick plate at 200 yards, you bet they will be adequate for hunting. They made more of a dent than the mil surp ball I shot it with.

[geargnasher]

Lots more good information here. I think any decent handloader that goes down this road will come up with the same results with boring regularity.

Perfect example: Last weekend I took out one of my M70s and shot the Lee 185-grain GC boolit to right at 2000 fps, perhaps a bit more, with 50/50 water-quenched alloy at 18 bhn using 39.5 grains of H4350 and maintained just over MOA at 100 yards. I went to 40.5 grains and got up to about 2045 fps, 10-shot groups opened up to 2". At 40.5 grains I exceeded two things: Larry's maximum recommended RPM of 140K, and Richard Lee's maximum recommended pressure for peak accuracy with 18 bhn alloy according to the Hodgdon pressure data for the boolit and charge weight I used. I don't care who's right on the theory, but I've proved several times now that this gun and boolit will not get peak accuracy faster than 2K fps with this boolit, alloy, and powder, and repeatable truth on target trumps all. I consider a 185-grain boolit made out of malleable quenched alloy at even 1900 fps to be quite a killer, and if I were to dope out the actual trajectory and get very comfortable with it from 50-200 yards I wouldn't feel under-gunned in any hunting situation I'd likely encounter in North America.

My other M70 .30-'06 will maintain 1 MOA to somewhere in the 2300 fps arena, and 2 MOA to nearly 2700 fps (the pressure limit with the boolits I use for it), but it is NOT a hunting boolit, and the amount of prep work and fitting required to make it do this with any consistency is insane. Think 28 bhn boolits and match prepped everything.

Gear

[Recluse]

And I still need to order some better lube, although I am fairly impressed with the 45/45/10 for standard velocity uses.

Add some beeswax to it (45/45/10) for hardness--you can then either pan lube with it, or pour it into pvc molds and make lubesticks.

I got my best group of all using that lube. (And I simply quit concerning myself over leading with that lube combo--it just doesn't happen.)

:coffee:

[Larry Gibson]

Gear

In the example you give the RPM threshold and Lee's maximum psi do not disagree. Exceeding the maximum alloy strength does allow for potential unbalancing of the bullet during acceleration. If unbalanced to a good degree the adverse affects of exceeding the RPM threshold, i.e. loss of accuracy, become imediately apparent. Strange thing is sometimes a malleable soft alloy in a correctly designed cast bullet sets back evenly during accelleration and the bullet remains as balanced as when loaded. Thus the RPM threshold can be pushed up with accuracy maintained even though the Lee maximum psi has been exceeded.

Larry Gibson

[Recluse]

Gear

In the example you give the RPM threshold and Lee's maximum psi do not disagree. Exceeding the maximum alloy strength does allow for potential unbalancing of the bullet during acceleration. If unbalanced to a good degree the adverse affects of exceeding the RPM threshold, i.e. loss of accuracy, become imediately apparent. Strange thing is sometimes a malleable soft alloy in a correctly designed cast bullet sets back evenly during accelleration and the bullet remains as balanced as when loaded. Thus the RPM threshold can be pushed up with accuracy maintained even though the Lee maximum psi has been exceeded.

Larry Gibson

I'm wondering if the harder alloy results in slower moving mass of molecules, thus resulting in greater stability in flight via the RPMs having a gyroscopic type of stabilizing effect on the projectile?

Softer alloy would/should have faster moving molecules which would not be as stable, thus not allowing the same/higher RPMs, which in turn reduces the gyroscopic stability of the boolit.

Likewise, perhaps why moderately slower burning powders will yield better results in moderately higher velocity rounds? I'm familiar with gyroscopic effects and stability as they pertain to some of the navigation instruments we use in airplanes. If a gyro spins up TOO fast, it can result in it becoming unstable if any little thing is off while it is "spooling up."

It would seem that trying to push a long, heavy boolit TOO fast out of the gate could give the same result, which we would call a flyer?

:coffee:

[nanuk]

Gear, I'm not a machinist, but here is a thought

get a 7/8x14 coupler

get a 7/8x14 piece of allthread

ream out a centered hole through the allthread 0.001 larger than the boolit diameter

get a piece of stock and turn it down to boolit diameter

get the end turned to match the noseform of the boolit

grind the top off a seating die to the top of the "Neck" and relieve the outside to allow the coupler to screw down to replace the lockring

screw the coupler down on to the die

screw the allthread into the coupler down tight on the seater

insert a dummy round and lower the nosepunch down into the allthread and note the amount to remove, so you can just hammer the nose punch down onto the boolit to seat it to your desired depth (perhaps you could thread the top of the nose punch to adjust for depth) and install some form of ball on it to hammer on, or to use your hand

use the nose punch to seat the boolit, a la LeeLoader

Voila, poormans inline seater

to make it more exact, you could use a sizer, lap it out with YOUR fired cartridge, (or make an impacted cartridge full of lead) so you have an exact fitment.

as I said, I'm not a machinist, but I can visualize this...

[runfiverun]

recluse:
in the bbl it's called slumping.
if you find or capture a boolit that has exceeded the plasticity of the alloy.
it will change shape in the Bbl.
or off set the less supported areas, sometimes to the side, sometimes rearward.
you are usually skidding over the lands in the bbl too.

after chasing what you have been chasing i just got a 30-30 and went to 2300 fps and called it a day.
next step, the 14 twist bbl pushed by 45 grs of powder in a long necked 300 savage case.

[geargnasher]

...or you can wrap them in paper and shoot them to nearly 2700 fps with ACWW and have J-word accuracy! Am I starting to sound like Pdawg Shooter? (not that that's a bad thing).

Gear

[Nobade]

Hey, that's cheating! It makes this too easy.

[Larry Gibson]

runfiverun

after chasing what you have been chasing i just got a 30-30 and went to 2300 fps and called it a day.
next step, the 14 twist bbl pushed by 45 grs of powder in a long necked 300 savage case.

I had the exact same thought back in the early '80s. I call it the 308 CBC (Cast Bullet Cartridge). The basic idea was a case with the capacity of the 300 savage with the neck of the '06. Photo shows it next to the .308W.

My problem with it is that back then I had no idea about the RPM threshold. I had a new 2 groove '03A3 barrel that every one touted as the cat's meow for cast bullets so that's what I chambered it in. It works fine but is limited by the same 10" twist as the '06 and in reality does no better accuracy wise above 1950 fps, even with the smaller capacity case. Had I known then what i know now it would have gone in a 14" twist 26" barrel.

Knowing that I am seriously considering a 30x57 in a 14 or possibly even a 16" twist barrel at aminimum of 26" length but more probably a 28" barrel. Next photo shows it on the left with it's parents on the right; the 8x57 and the '06. It's easily made by just shortening an '06 FL and seater dies. Case acapcity is about half way between the .308W and the '06 so 2700 - 2800 fps should be quite feasable pushing the 311466 or the LBT 150 gr bullet over AA4350, H4831SC or perhaps RL22. If the case capacity is not there for the slow burners it can easily be rechambered to straight '06.

Larry Gibson

[Dthunter]

Once you find your load with the pistol powders that shoots good, and you know your boolit size and lube are right, then if you so choose to progress to the rifle powders you can. I learned long ago to get a gun shooting good with pistol powders before moving on to rifle powders. It looks like you are most of the way there.

Quote "Boerrancher"


This I aggree with, it gets you prepped for shooting that particular rifle, and it gives you an idea of what pressures your alloy will likely perform well with slower rifle powders.

Have fun guys!

[Dthunter]

Trey,

It is great that you are getting your '06 to shoot cast really well. My 03A3 is a so so cast shooter, but it is all original military. One thing I learned with my 30-30 and my '06 is to not be afraid to try some of the faster rifle powders like IMR3031, through IMR4064. I have found that some of my best cast groups have been shot with 3031 powder @ 100 yards. Once you find your load with the pistol powders that shoots good, and you know your boolit size and lube are right, then if you so choose to progress to the rifle powders you can. I learned long ago to get a gun shooting good with pistol powders before moving on to rifle powders. It looks like you are most of the way there.

Joe


X101airborne

Myself and numerous others have worked bullets such as 311291, 311041 and several other cast bullets of the bore riding nose design every which way at higher velocity. Normally best accuracy comes in the 1700 – 1900 fps range as reported. That is within the RPM threshold for the 10” twist. You may or may not believe there is an RPM threshold but it’s what’s giving you larger groups as you increase the velocity and RPM above 1950 fps. Working different alloys, powders, sizing, GCs and lubes I was able to maintain 2 – 3 moa at 2200 – 2300 fps with the 311291 for consistent 10 shot groups at 100 yards. If you want to improve on that accuracy at or perhaps a little higher velocity I suggest you change bullet designs and pay particular attention to minute details when casting and loading.

Bullet; with the ’06 the ideal cast bullet design is one that has minimal lube groove depth with enough lube for the length of barrel. It should have a short nose with minimal ogive of not more than caliber length. The bullet should have a bearing length from the beginning of the ogive to the base of the GC. That bearing length should just fit within from the base of the cartridge neck to the beginning of the leade. Two designs fill those requirements in most ’06 chambers; the Lyman Lovern design 311466 and the LBT 150 gr. With either bullet design moa accuracy with 3 -5 shots is obtained with proper casting, sizing and loading in the 2200 – 2300 fps range if the rifle/shooter are capable with a 10” twist rifle. With either cast bullet such accuracy (1 – 1.5 moa w/10 shot groups) can be obtained at 2400 – 2500 fps with a 12” twist and 2600 - 2700+ fps is possible with a 14” twist.

Alloy; I’ve found a strong yet malleable alloy of 18 – 22 BHN to work best. A hard brittle alloy with a high antimony content should be avoided.

Cast bullets; they should be visually inspected under a magnifying glass for any defects. If using a multiple cavity mould they should be weight sorted if they do not weigh the same from each cavity.

Gas Checks; bullet bases must be square and flat. If the sprue cut of is not even with the bullet base cut a sharp knife can cut it flat. GCs need to be soft so annealing them may be necessary if they are commercial. I use my own made from .015 brass shim stock. The GC should be a tight slip fit on the bullet shank. It should not be forced on and swage the flat bottom of the shank. A GC seater (I use the Lyman on a 450 with a .311 H die) should be used to squarely seat the GC and crimp before sizing. I then Push size the bullets through a Lee .311 sizer after a light spray of Dillon case lube. Only then are the bullets lubed in a .311 H die in the 450.

Bullet lubes; I’ve run multiple tests at HV with various commercial lubes. I consistently get the best accuracy with Javelina lube followed by 2500+. At high velocity/RPM the bullet lube needs to spin off very quickly and completely. Hard lubes do not and small chunks of lube sticking to one side of a cast bullet will unbalance it with inaccuracy being the result. Softer lubes work best at HV and I’ve yet to find one that betters Javelina.

Cases; should be “match prepped”, well fire formed, neck sized with .002 neck tension, with uniform neck thickness.

Powders; I’ve had best results with AA4350, RL19 and H4831SC. If loading density is below 80% I use a dacron filler.

Primers; I’ve also ran numerous tests with different primers. “Soft” primers will lower velocity and RPM with these slower burning powders. Accuracy will appear to be better but it is the lower velocity/RPM from such. Load all to the same velocity/RPM and it’s hard to pick a “best” primer. I mostly use WLRs because that’s what I buy in bulk. Magnum level primers are not needed in the ’06 with these powders and give higher SD/ESs which isn’t good for accuracy.

There you have my advise based on “been there, done that” numerous times. My best advise if you want jacketed bullet accuracy at jacketed bullet velocity in and ’06 is to get a quality 14” twist barrel 26”+ long and follow the advice I’ve given. You will be amazed at how easy accuracy at HV then comes with cast bullets, even with 311291 and 311041.

Larry Gibson


Well put Larry! I deal with a rpm related Subject every day at work.
I am a Journeyman Millwright who takes vibration readings on various equipment.

As rpm increases, so does centrifical force. Increased velocity induces this effect.
Every rotating element/bullet has a "natural frequency" built into its design. "EVERYTHING" no exceptions.
A given design will find its sweet spot at certain RPM's.
Every time a rotating element goes through an exccelerated rotational speed, it will incounter "critical speeds".
This is a rotational speed where a given element will start to destabilize. If the rotational speed is quickly accellerated through this critical speed area, the rotating element (bullet) will again stabilize, and allow for increased rotational acceleration.

If the bullet is exccellerating into and Past any of these critical speeds, it is not a big deal, because it is fully supported by the bore. But if the bullet is released from the barrel near one of these critical speeds, accuracy will suffer.
Thats why "I believe" certain bullet styles TEND to shoot best at specific velocities.
Larry mentioned that tendancy as well.

Bullet alloy strength and resiliency will further govern its rotational(rpm) limits.

But more than anything, voids/inclusions, wrinkles, etc will cause pure havoc on a bullets ability to deliver consistancy. This causes severe off axis stresses on a rotating element(bullet).
Thats why it is so important to segregate your bullets. Minimize your potential for flaws.

When starting up power generators/Steam Turbines, worth multiple millions of dollars, the equipments shaft/rotating element will encounter many of these "Critical Speeds". We have to aggressively accelerate the equipment through these "nodes", till we reach operational speed.
I believe an unsupported bullet in flight has many hurdles to encounter!
Consistant loading practices, velocity selection/potential rpm, etc, are all part of the loading recipe for precsion/accuracy.

Thats my .02 cents on this.

[Dthunter]

When a bullet/ load is being developed, when you reach that point where a given load starts to open up (groupwise), a shooter has to figure out if the load/rpm is at its "critical speed", or at the bullet/alloys limit.
The loading manuals typically have the "pressure window" for a given alloy listed by the loads they reccommend.
If your load experiment is going in incremented grains of a given powder, you will notice a trend in group size/and load stats ( S.D, E.S,Velocity). If a load suddenly sprays all over the target,(and If previous loads shot well) You either have reached a component pressure limit, or a critical speed with your load.

Hopefully I explained that clearly.
Share your thoughts on that guys. I am open to critical thought.

[brotherdarrell]

I am going to try not to sound like a total kook here and ask that you bear with me as I try to ask a question.

***
As rpm increases, so does centrifical force. Increased velocity induces this effect.
Every rotating element/bullet has a "natural frequency" built into its design. "EVERYTHING" no exceptions.
A given design will find its sweet spot at certain RPM's.
Every time a rotating element goes through an exccelerated rotational speed, it will incounter "critical speeds".
This is a rotational speed where a given element will start to destabilize. If the rotational speed is quickly accellerated through this critical speed area, the rotating element (bullet) will again stabilize, and allow for increased rotational acceleration.
****
I worked in and alignment shop for several years and one of the problems we had to deal with was vibrations of all sorts, and diagnosing and fixing said vibrations. The 'balancer' checked several things when tires were spun, one of which was an out of round tire/wheel assembly, and quite frequently we were able to spin the tire on the rim and match high/low spots and heavy/light spots and improving felt vibrations. Not new tech by any means. When diagnosing this one characteristic was that the vibrations showed at intervals, ie. 35 &n 70 mph but not at other speeds; or at 30 & 60 mph. You may feel at 30 but not above until you hit 60, and at some point you could "drive through" the vibration and have a smooth ride. So.......

Is it maybe possible to "shoot through" an imbalanced boolit/rpm threshold, maybe? My 10" twist 788 .308 gives fits at 1900fps and above; is it possible faster could be better, or should I leave the heavy thinking to those more cerebral and analyticaly gifted? Now my brain hurts.

brotherdarrell

[Larry Gibson]

brotherdarrell

You are certainly welcome to attempt to "shoot through" the RPM threshold. Many of have tried and all of us have failed. Some of us comprehend the problem (balanced bullet going in barrel, unbalanced bullet coming out because of increased acceleration and the increased RPM adversely affect the accuracy). With a given twist barrel the only way is to push the RPM threshold higher with appriateldesigned cast bullet and to slow the accelleration rate with a slower burning powder. At some point you will come against the RPM threshold and accuracy will suffer.

The other, and most successful method is to; use a case with enough capacity to use the slower burning powders and reach the target velocity with the chocen bullet, the chosen bullet should be a correctly designed cast bullet that will minimise unbalancing during accelleration and lastly to control the RPMs so the bullet stays under 140,000 RPM at the target velocity with a slower twist long barrel, preferably 26"+.

BTW; the M788 with 10" twist at 1900 fps is at 136,800 RPM. Depending the bullet your using, the alloy, the fit and the powder used that sounds about right for accuracy to start going south.

Larry Gibson

[waksupi]

It has probably been posted, but I don't see right off hand. Can someone give me the mathematical formula for figuring fps and twist rate? I suck at math.

[Larry Gibson]

MV (FPS) X 720 / twist (in inches) = RPM

That's off the top of my head....did I get it right?

Larry Gibson

[brotherdarrell]

Larry, thanks for the response. My post was an example of me typing(thinking) out loud. Two rt. shoulder surgeries in the last two years makes me think I would'nt try to shoot through the imbalance, but I have read most of what you have to say on this subject and am trying to apply it to my 788 (200gr lee, by the way).

You did have something in your post I am not sure I have read before

*****The other, and most successful method is to; use a case with enough capacity to use the slower burning powders and reach the target velocity with the chocen bullet, the chosen bullet should be a correctly designed cast bullet that will minimise unbalancing during accelleration and lastly to control the RPMs so the bullet stays under 140,000 RPM at the target velocity with a slower twist long barrel, preferably 26"+.*****

.......you say 'during acceleration', which to me means in the barrel Please correct me if I am reading that wrong, as I don't want to mis-quote what you are saying, but are you saying that the slower/longer(ie. 4831,4350/26" barrel) that is used to get to velocity/rpm the more you can push max rpm before imperfections in the boolit cause imbalance detrimental to accuracy?

I really hate it when my anal side comes out. I would also ask that if one was to cast a perfectly balanced boolit, would this threshold exist and if so at what point?

brotherdarrell - just questioning what I think/believe to be true - ignorance is not bliss

[Larry Gibson]

.......you say 'during acceleration', which to me means in the barrel Please correct me if I am reading that wrong, as I don't want to mis-quote what you are saying, but are you saying that the slower/longer(ie. 4831,4350/26" barrel) that is used to get to velocity/rpm the more you can push max rpm before imperfections in the boolit cause imbalance detrimental to accuracy?

You are reading that quite correct. Slower and longer time/pressure curve is better and is indeed what I'm saying.

I really hate it when my anal side comes out. I would also ask that if one was to cast a perfectly balanced boolit, would this threshold exist and if so at what point?

While I like to think I cast a perfect bullet I really suspect I don't. Probably not many that do. Theoretically let's say we do cast the perfect bullet, let's say we load it in the cartridge with perfect concentricity and let's say the cartridge and bullet fit "perfectly" in the chamber and throat then the trick is to get it down the barrel and out the muzzle in perfect condition with perfect balance. IF we could do that then the bullet would be "perfectly" balanced and there would be nothing for the centrafugal force to act upon as the force would be equal in all directions. Then all we would have to worry about is yaw, pitch, stability, the wind, mirage, etc. ad nauseum...........

The trick is getting the bullet out the end of the barrel as balanced as possible. The faster you drive it the more adverse affect intertia will ,can and does have on the bullet during internal ballistics (while in the barrel). The higher the RPM the greater the adverse affect during flight (external ballistics). At some point past the RPM thresh hold the cast bullet will either take off at a tanget to the line of flight or will begin a slow helical spiral away from the line of flight that is non linear as range increases, i.e. accuracy really begins to suck:cry:

Larry Gibson

[Gunor]

Larry,
Really enjyed your response about the loading process (thread #25 on page 2).
RPM interesting....
So I am good if I have an extra palma gun laying around with a 13 twist (might even have a 14), 308 and 30" long?
I am just looking for nice easy load to shoot in the backyard (100yards) that can be accurate (low velocity 1600-1700)

BTW - I just ordered a Lee C-312-155 - that I was hoping would fill a few bores. Mosins (Finnish Only), Ross, P-14, No 4, Mk II (FTR)

Geoff in Oregon

[waksupi]

MV (FPS) X 720 / twist (in inches) = RPM

That's off the top of my head....did I get it right?

Larry Gibson

Larry, like I said, I am a total idiot at math. So I multiply fps, times, 720, times twist? Is that how I need to read that?
Maybe the easy way to ask, is what is my top velocity in a 1-14 barrel?

[Dthunter]

This shooting stuff really gets interesting doesnt it? LOL!
Its all about finding the balance for a given bullet. Velocity/pressure/twist rate etc.Some times its easy, sometimes not so much so.

Fast twist barrels are fine for a j-word projectile (to a point). We as lead based alloy shooters are limited to the shear strength of our chosen material. If a slower twist rate is employed, we can drive them faster, before the bullet experiences the gyroscopic forces great enough to surpass the bullet alloys yield strength.

This yield point can be surpassed by too much "Ultimate pressure", or pressure applied too fast. A huge, wide variety of powders that are available today make our choices more flexible than ever. I believe "normally" the slowest powder you can use and still get consistant ballistics, (low standard deviation, and Extream spread), and clean burning is your best choice.



And, as far as rpms are concerned this came to mind:

I have seen and heard long range tactical shooters talk about accuracy "nodes". They talk about experiencing a "trend of groups getting larger, then smaller, and bigger again". or visa versa.
This, in my estimation/opinion, shows "me" that the tendancy of rpm/critical speeds theory bears some fruit.

I have experienced this when load developing for a .308win and 300Win mag. at distances like 1000-1200yards.

There are allot of physics to stable bullet flight. Things like "Dynamic Overturning Torque" come into play in a bullet that is understabilized. I saw this when shooting at 1400yards with my 165grain Berger VLD's in my .308win. My bullets were just shooting great at 1300yards, but you could see the bullet holes were starting to get out of round. That extra 100 yards evaporated the bullets stability limit. Interesting stuff!

I hope to figure all this cast bullet shooting stuff out! It sure is enjoyable!

Have fun guys! thats what it is all about!

[uscra112]

Examples given of "critical speed" are all cases where the rotating object is constrained by a surrounding structure. It's the harmonics of the structure that create conditions where vibration will occur at one RPM but not another. Been there, done that, wore out the T-shirt. A boolit after it has left the muzzle is not constrained. Different kettle of fish.

[geargnasher]

No Ric, multiply fps times 720, divide that number by your twist in inches, and you have your RPM at that velocity.

2000 fps times 720 = 1,440,000. Divide that by your twist rate in inches, say 10, and you get 144,000 RPM.

The 720 factor is your feet converted to inches (so you have a common denominator with the twist rate in the next operation), then multiplied by 60 to convert it to "minutes", again to yield an answer in "rounds per minute".

I think we can all agree that RPM both makes sense and doesn't, we're familiar with it from working with engines and driving vehicles with tachometers so it's a common frame of reference, but when shooting it should really be rounds per second since we use feet per second to discuss velocity. I'll stick to RPM because Larry invented it and we all know what he's talking about.

Oh, Larry, not to stir the old pot too much, but you are flat out wrong when you said that none of us have ever succeded in beating the RPM threshold (or resonant frequency, or radial vibration as it may be called). It isn't easy, but it's possible at least some of the time, I did it a few years ago before I ever found this forum and learned that it was supposed to be impossible. Now I know why it's so dadgum difficult.

Gear

[Dthunter]

Thats muzzle velocity (in feet per second) multiplied by 720, then divided by your rifling twist (in inches).

example:

3000feet per second, multiplied by720, then, the resulting sum is divided by 10 (for a 1 in 10" twist).

which is: 216000 divided by 10.

this equals=216000rpm

How is that?

[x101airborne]

Larry needs to be called the "Dahli Lama" of the cast boolits world. We come to the mountain to gain knowledge and enlightenment. Seriously Larry, it is nice to get information from someone who knows the "why" of the problem. Hats off to you.

I shot this rifle some more this weekend. I am getting good groups at 100 yards, about 5/8 inch for 5 shots. 200 yard groups open up to around 2 inches. Wich, is doable and for a hunting rifle, is better than is necessary. Bullets hit with a good WHUMP, recoil is negligable (even for my wife who is a new shooter). I have not shot an animal yet, so that is to come. Two water jugs explode when shot but not fully penetrated the third, so for our light game, I think the alloy is just about right. I have not chrony'd these, but I am wanting information from the target, not the chrony.

[nanuk]

I still have trouble with the RPM theory (?) and PP boolits... why would wrapping some paper around some lead make the RPM theory not applicable?

perhaps the "RPM" is an effect, and disguises the real factor?

it is rather moot though, cause if one adheres to the RPM, they will be in the range.

it is kind of like the WeatherMan harping about the Jet Stream, cause it sounds cool, BUT the Jet Stream is Caused by other factors and does not create weather on it's own, and as I was taught, it creates NO weather, only turbulance. The actual weather is created by the frontal zone's interaction with the tropopause

[blackthorn]

Gear---you said:
“The 720 factor is your feet converted to inches (so you have a common denominator with the twist rate in the next operation), then multiplied by 60 to convert it to "minutes", again to yield an answer in "rounds per minute".

Did you mean "revolutions per minute"?

[brotherdarrell]

I still have trouble with the RPM theory (?) and PP boolits... why would wrapping some paper around some lead make the RPM theory not applicable?

perhaps the "RPM" is an effect, and disguises the real factor?

it is rather moot though, cause if one adheres to the RPM, they will be in the range.

it is kind of like the WeatherMan harping about the Jet Stream, cause it sounds cool, BUT the Jet Stream is Caused by other factors and does not create weather on it's own, and as I was taught, it creates NO weather, only turbulance. The actual weather is created by the frontal zone's interaction with the tropopause

nanuk - thats where my line of thinking has been going lately on this subject, and why a little flag went up when Larry stated that this happens in the barrel.

For the last year anytime the phrase 'rpm threshold' is used I instantly translate that to 'bullet uniformity threshold', which to my way of thinking is the root cause here, due to the reason that a uniform bullet would not have a threshold. Yes, this is semantics, but for my way of looking at this it is what I have to do.

As far as pp vs. not there is obviously something changing the equation, and it appears to be the interface between boolit and bore. The alloys are not changing, nor is the mold quality in most cases. So what is changing? Contact between boolit and bore, and if in the barrel is where this all starts what part of the barrel is effecting this and can it be altered if identified?

boy, talking about posting above my knowledge level!!! - I really need to go back to work.

brotherdarrell

[Dthunter]

Hi Nanuk!

I dont think the rpm is "directly" limited/ the cause. I feel the the rotational torque/stress from a bullets transition from static to dynamic is.
Physical alloy properties ( hardness, tensile strength, toughness, etc) governs the bullets ability to pass or fail at a given stress level.

Slower twist rates will transfer this change of static to dynamic at a slower rate.
This would naturally allow us to push the bullet faster forward until the rate of static to dynamic torque starts to reach the alloys stress limit. Thats why the 1:12 & 1:14 twist rates allow faster axial/ forward/fps movement before the bullet starts to yield to the torque pressure.

I feel that rpm can be used with "relative" accuracy because most of use use similar alloys. Within limits of course.
Paper patch bullets dont deform the bullet as much to achieve the mechanical torque.
So when the seal fails, i would suppose the amount of damage the bullet incurs would be less on average. As compared to the fully engraved/ standard lube boolet.

Paper patching by virtue, simply tends to be more forgiving for velocity.
Accuracy wise I am not sure. I have never paper patched "yet".
It sounds very interesting and I will try it eventually.

Have fun guys, and give me your thoughts.

[Char-Gar]

I think the RPM stuff is valid and am glad folks can quantify it for those who have interest and/or need of such information.

In my shooting, it has never been a limiting factor, as I have never, nor do I intend to push that envelope. I am content these days to shoot itty bitty groups at "slow pitch" speeds.

Sure am glad some of you guys are more curious than I am, as everybody profits.

[geargnasher]

Gear---you said:
“The 720 factor is your feet converted to inches (so you have a common denominator with the twist rate in the next operation), then multiplied by 60 to convert it to "minutes", again to yield an answer in "rounds per minute".

Did you mean "revolutions per minute"?

Yes. :killingpc

Gear

[Dthunter]

Heres a thought.
If a paper patch bullet gasket interface (patch/bore fit relationship) fails, the paper will rupture and allow large volumes of gas to escape. This would result in huge velocity variations, and a some what damaged boolet suface.

If a standard boolet sized to use the alloy/lube (direct mechanical interface connection) to seal And starts to allow gas escape(for what ever reason) the surface of the bullet is greatly affected. the surface gets high pressure/velocity abasion. (most of us shooters seem to aggree with this point).
This damage causes a major instability (gyroscopically) evenbefore it leaves the barrel. Much the same as flaws or voids in a bullets alloy. Gas escaping out one side of the bullet base will compound this effect off target axis.

The standard type of cast bullet/ bore relationship has allot of physical conditions to satisfy, in order to give satifying results. This is the challenge.

Its human nature to push the limits of our gear. Some times such as our situation, many different things/variables have to be juggled at once. Its when we succeed at this that it gives us satifaction.

Satisfaction is what we all are chasing.

Hopefully thats not too philosphical! Lol!

[Dthunter]

Uscra112:

I respectfully dissaggree with your assessment.
You are saying that a bullet doesnt experience instabilities due to rotational torque/stress? Because its unsupported? I think thats misguided IMHO.

The supporting structures will always induce a vibration, because they "too" have a natural frequency, and cant help but contribute to the end cause.
Been there done that as you say.

Besides, its the best example that I can come up with that would explain some of these "TENDANCIES".
Can you give us "your thoughts " on the rpm/stability issues?
If you have been there-done that, maybe you have something contribute?

That is a question, not a sarcastic retort. We all want to learn here, not argue.

[geargnasher]

I still have trouble with the RPM theory (?) and PP boolits... why would wrapping some paper around some lead make the RPM theory not applicable?

perhaps the "RPM" is an effect, and disguises the real factor?



That's exactly right. If the RPM threshold theory was mostly a factor of the imperfections in boolit balance within a certain window, the paper woldn't to anything to help once the boolit left the gunbarrel, in fact it would do the opposite because there has to be some disturbance when shucking the patch, not to mention the patch trailing edge impression on the side of the boolit, which causes more of a balance defect than most of my internal casting flaws ever do.

Larry explained to me that the patch supports the boolit better in the barrel so it gets deformed less and flies truer, but I don't believe that. It's just paper. Paper will not prevent nose slump, it won't keep the base from riveting, or deformation in the throat upon firing, all things that he says contibute to the RPM threshold. My patched castings are often made from the same alloy and same moulds as my un-patched ones, and when shot in the same gun with the same exact load, well, you can imagine how that worked!!

My theory is that there is something other than balance causing this RPM thing, because all else being equal, a scrap of paper can literally add a 50% increase to velocity and actually increase accuracy while doing so.

In the smokeless PP forum I just posted where I fired a 3/8" five-shot test group at 50 yards at over 2700 fps with 13 bhn WW alloy (granted, just one group, I need to shoot that load a lot more), out of a ten-twist sporter rifle. That's 196,128 RPM if my chronograph is right. Record group for the gun, record RPM, only difference was boolit design and paper. Same gun groups at best about twice that size with anything else, often worse, and at 2K fps being about the limit with 17-18 bhn alloy and gas checks.

So somebody please 'Splain me about what's going on with the paper jacket that miraculously makes an ordinary, imperfect, casting and turns it into a laser? I can see only two things: The patch makes a perfect seal, and the patch strengthens the surface of the boolit where it keys into the rifling so it can withstand higher forces within the barrel. Once outside the barrel, you can't convince me there's any significant difference in flight between a boolit launched with lube and a gas check and a boolit launched with a paper jacket.

Gear

[Char-Gar]

Gear...Again, I don't want to play with the big boys on this issue, as I know when I am out of my league. But your post jostled some old memory on the RPM subject that took place quite a few years ago, maybe before you came along.

When discussing why RPMs were a liming factor on cast bullets, some of the big boys postulated, it was the pressure from the top edge and side of the rifling lands that was the rpm boogie man. This caused bullet distortion will all of the effect of that.

If that is true, and I don't know if it is, would that not explain why a paper patch would have the effect it does. The patch would take most of the rotational pressure of the edges and sides of the lands resulting in better accuracy from the bullet itself. A patch won't cure nose slump and base riveting as you said, but it might help with the unbalance created by sideway pressure of the lands.

Again, on this subject I am as dumb as the dog that did not know "come" from "sic-um". Just repeating what some of the big boys said.

[geargnasher]

I think that's right, Char-Gar. The boolits I last shot were soft, spire point boolits with no lube grooves, and no filler whatsoever. Plenty of opportunity for nose slump and base damage, yet they shot better than GG boolits did with checks and filler. That pretty much tells me the secret is in the strength of the surface of the boolit and its ability to take and hold the rifling cleanly and firmly without leaks or damage. Interestingly, that's the secret of copper-jacketed velocity and accuracy too.

Gear

[dmitch]

Geargnasher,
That helps my understanding a little more on a project I worked on last summer using a 10" twist 30-06, 30 cal sabots with a 22 cal jacketed (50 & 55 gr.) and 22 cast boolits (225438 & 224450 Hollow point, no checks). Helps explain how the cast boolits could rev to 266,544 rpms (the 225438 at 3702 fpsX720/10) and often shoot more accurately than the jacketed saboted bullets at 100 yds. All projectiles grouped from 3-5 inches (5 shots) at 100 yds including the Remington Accelerators I found in my junk. 3 shot groups were normally 2-3 inches when throwing out the flyers....but that isn't really fair. So the project continues this summer. Not what you want to see for varmint accuracy, but I seem to be learning a lot. That 224450 HP does a job on a woodchuck inside of 100 yds!!!!
dmitch

[felix]

Rule: Never overtwist (rotational accelerate) any kind of projectile from a dead stop to desired RPM. Obamamation anyone? ... felix

[geargnasher]

Ahh, and so enter the theory behind the "gain twist" rifling cut.

Whatever the case, slow powders and slow twists will get higher velocity with the same accuracy potential, or you could just paper patch and not worry about it, or work within the "RPM threshold" of your weapon system and not worry about it. Either way works just fine.

Gear

[tonyjones]

Consider this. A jacketed bullet, as long as the core and jacket are not separated, is a composite material. It is neither core or jacket but a composite of the two. Therefore, the structural properties of a jacketed bullet must be considered as a composite material with "greater" structural characteristics than the lead core or the jacket alone. Perhaps a paper patched bullet, as long as it's in the rifles bore, is a composite material as well.

I'm going to take shelter now. INCOMING!!!

Regards,

Tony

[Dthunter]

Lol!

I am curious about paper patch for sure!
Seems like more work, but ultimately better.

[Larry Gibson]

Larry, like I said, I am a total idiot at math. So I multiply fps, times, 720, times twist? Is that how I need to read that?
Maybe the easy way to ask, is what is my top velocity in a 1-14 barrel?

No; it is muzzle velocity in fps times 720 divided by twist in inches. I.e.; 1900 fps x 720 = 1,368,000 divided by 10" (twist) = 136,800 RPM. That's your typical '06 at 1900 fps.

In my 14" twist .308W with 27.5" barrel I am pushing over 2600 fps with 10 shot 1.5 moa accuracy to 300 yards with my 311466U. That is 133,714 RPM at 2600 fps. My problem in going higher is one of case capacity or lack of it. I am just able to get 50 gr of AA4350 in the fire formed WW Palma case. A faster burning powder can get higher velocity/RPM but the accelleration is right at the edge as accuracy falls off at 2570 fps so the acceleration is to fast with the faster powder. I'm seriously looking at an '06 one of these days with a minimum 14" twist and probably a 16" twist. Should be able to push 2800 - 2900+ fps with a slow burning powder at 126,000 - 130,500 RPM with that barrel using the 311466U cast bullet.

Larry Gibson

[Larry Gibson]

Gear

I didn't "invent" the RPM threhold and didn't really discover it either. I began reading others questions and assumptions regarding what was happening to cast bullet accuracy at certain velocities. Perhaps I just better defined it as an RPM threshold is all.

I'll also bet you did not exceed the RPm threshold back then. If we take a close look at it you probably just pushed it up pretty high. Perhpas you cast, loaded and launched "the perfect cast bullet" as another poster querried about? Note I've always said the RPM threshold is not a fixed number, it can be raised up or moved down but wheter it can be crossed is doubtful. The laws of ballistics and physics are what they are.

Larry Gibson

[Char-Gar]

I think that's right, Char-Gar. The boolits I last shot were soft, spire point boolits with no lube grooves, and no filler whatsoever. Plenty of opportunity for nose slump and base damage, yet they shot better than GG boolits did with checks and filler. That pretty much tells me the secret is in the strength of the surface of the boolit and its ability to take and hold the rifling cleanly and firmly without leaks or damage. Interestingly, that's the secret of copper-jacketed velocity and accuracy too.

Gear

Gear...I think you have hit the essence of what the RPM thing is all about. That is my best guess also.

[Larry Gibson]

I still have trouble with the RPM theory (?) and PP boolits... why would wrapping some paper around some lead make the RPM theory not applicable?

perhaps the "RPM" is an effect, and disguises the real factor?

it is rather moot though, cause if one adheres to the RPM, they will be in the range.

it is kind of like the WeatherMan harping about the Jet Stream, cause it sounds cool, BUT the Jet Stream is Caused by other factors and does not create weather on it's own, and as I was taught, it creates NO weather, only turbulance. The actual weather is created by the frontal zone's interaction with the tropopause

The RPM threshold is applicable to PP'd cast bullets. It just happens the RPM threshold for PP'd bullets is much higher, many times higher than the possible velocity produced RPM the cartridge is capable of. Just as with regular cast bullets; you can push a linotype PP'd bullet to a much hgher velocity/RPM in an '06 than you can push a lead PP'd bullet. The difference is the PP potects the cast bullet from the adverse affects of accleration as does the harder alloy.

Larry Gibson

[Larry Gibson]

nanuk - thats where my line of thinking has been going lately on this subject, and why a little flag went up when Larry stated that this happens in the barrel.......brotherdarrell

It is the deformation/unbalancing of the bullet during acceleration that occurs in the barrel. The faster the accelleration to a given velocity with a given alloy the greater the deformation/unbalancing that will occur. We can lesson this by using a properly designed cast bullet leaving little room of deformation, by using an alloy that will set back and deform evenly and by slowing the accelleration.

Larry Gibson

[geargnasher]

Larry needs to be called the "Dahli Lama" of the cast boolits world. We come to the mountain to gain knowledge and enlightenment. Seriously Larry, it is nice to get information from someone who knows the "why" of the problem. Hats off to you.

I shot this rifle some more this weekend. I am getting good groups at 100 yards, about 5/8 inch for 5 shots. 200 yard groups open up to around 2 inches. Wich, is doable and for a hunting rifle, is better than is necessary. Bullets hit with a good WHUMP, recoil is negligable (even for my wife who is a new shooter). I have not shot an animal yet, so that is to come. Two water jugs explode when shot but not fully penetrated the third, so for our light game, I think the alloy is just about right. I have not chrony'd these, but I am wanting information from the target, not the chrony.

What you have there is an example of "non-linear dispersion", where your groups open up disproportionately with range increase. Theoretically, a 5/8" group at 100 yards should print 1-1/4" at 200 yards and so on, but 'taint necessarily so, especially at and beyond the range that the projectile makes the subsonic transition.

I could be wrong, and will be corrected shortly if so, but I remember Larry explaining non-linear dispersion to be an effect of exceeding the RPM threshold. The boolit loses forward velocity downrange, but very little rotational velocity. Here is where Larry and I butt heads: He believes that an overspun boolit gets out of balance due to minute casting imperfections and damage it experiences while being fired, and that is amplified at extended ranges because the boolit begins to describe a helical path, which makes sense enough and jives with common external ballistic knowlege and a few embalanced bullet experiments that he's done, but it cannot explain why paper-patched boolits seem to be relatively immune to non-linear dispersion at extended ranges when they are no better castings than plain cast ones are, and are subject to much the same deformation forces within the barrel, with the exception of the engraving damage. He explains that the un-patched castings get damaged in the launching process more than patched ones and so they don't fly as well above the RPM threshold, which I think is true, but we cannot agree on just exactly WHAT gets damaged. None of his explanations of nose slump, accordion, crooked throat entry, etc. hold water because the patched boolit experiences the same forces and I don't see how it is any better able to resist them. The work I've done pretty much eliminates casting defects as a cause of the non-linear dispersion because the SAME BOOLIT from the same casting session can be shot under identical conditions patched and unpatched, and the patched ones shoot like or better than copper-jacketed bullets and the un-patched ones fly everywhere. It ain't casting defects, but I think it IS something happens in the barrel above a certain rotational velocity to cause groups to open up once the boolit is free of the gun.

Maybe, just maybe, like was mentioned a few posts above, the RPM threshold is not actually the CAUSE, but an effect of something else that happens to coincide with a certain rotational velocity window that Larry has identified as the easiest point within which to get peak accuracy. I tend to agree with that and think the jury is still out. Richard Lee thinks it all has to do with pressure and alloy strength, and within his stunted little paradigm, he's absolutely right. Larry knows about a bazillion times more than Richard ever will, but I don't think that simply calling "RPM" as the true culprit is any more appropriate or explanatory than "Pressure vs. yield strength". Too many variables even though certain trends do emerge. I'm not saying that the RPM threshold theory isn't a good way to understand a very real phenom, but I am saying that I don't think it's the only way to look at the issue when trying to troubleshoot it. Going to a slower twist is not the only way to skin this cat.

I've shot a lot of high-velocity groups at 100 yards that held tight but fell apart farther downrange. It's possible to keep it together at high speed and twist rate longer with regular cast boolits, but I've never been able to do it without, at the very least, extremely hard alloy, slow powder, and some downright stupidly obsessive case prep and loading practices. So much so that it really zaps the fun right out of the whole process.

Gear

[geargnasher]

It is the deformation/unbalancing of the bullet during acceleration that occurs in the barrel. The faster the accelleration to a given velocity with a given alloy the greater the deformation/unbalancing that will occur. We can lesson this by using a properly designed cast bullet leaving little room of deformation, by using an alloy that will set back and deform evenly and by slowing the accelleration.

Larry Gibson

I still think it all has to do with the engraves assuming a properly fit boolit to begin with. How that affects balance I can't figure out. Based on the results from shooting the same boolit patched and unpatched many times the only thing I can figure that changes is how the boolit holds the rifling under high acceleration forces. I would think that any deformation caused by the lands alone would be consistent and not affect boolit balance downrange. Thoughts? Please don't tell me that the patch prevents nose slump, accordion, or damage from entering a throat crooked, because paper isn't that sturdy!

Gear

[trixter]

I need to squeeze a question in here if I may? I have an 03-A3 that has been sporterized and I know I have not shot it too much and, my Step-dad that gave it to me didn't shoot it except for hunting season. That being said, I am wondering where to size my boolits that I am casting. They come out of the mold (and cooled for 24hrs) at .3105 +/- .0005. I am hoping that .309 will work, but needing some expert opinions. I have tried to find a .32 caliber round ball or 2 where I live and all of the shooting suppliers just look at my like I am NUTZ. (May be). I don't really want to order a box of them and use 2. I will keep looking, but just need some advice.

[Larry Gibson]

Gear

So somebody please 'Splain me about what's going on with the paper jacket that miraculously makes an ordinary, imperfect, casting and turns it into a laser? I can see only two things: The patch makes a perfect seal, and the patch strengthens the surface of the boolit where it keys into the rifling so it can withstand higher forces within the barrel.

I have explained it to you several times. The PP is a "jacket" that supports the bullet and lessons the adverse affect of accelleration. If the PP'd bullet isn't deformed as much during accelleration as the same bullet non PP'd given the same acceleration to the same velocity the PP'd bullet is better balanced. Being better balanced it will shoot more accurately. It's that simple.

Once outside the barrel, you can't convince me there's any significant difference in flight between a boolit launched with lube and a gas check and a boolit launched with a paper jacket.

Perhaps "you can't convince me" is the problem, you not got an open mind and can not see the answer. The "significant difference" is the PP'd bullet will be less deformed/unbalanced than the same cast bullet sans the PP. Ergo, being better balanced, the PP'd bullet will be more accurate. The PP'd cast bullet can be driven to a higher velocity/RPM before the adverse affect of accleration makes the imbalance the same as with the plain cast bullet at the lower velocity. Accuracy will then deteriorate as the PP'd bullet has reached the RPM threshold for itself.

Originally Posted by geargnasher
I think that's right, Char-Gar. The boolits I last shot were soft, spire point boolits with no lube grooves, and no filler whatsoever. Plenty of opportunity for nose slump and base damage, yet they shot better than GG boolits did with checks and filler. That pretty much tells me the secret is in the strength of the surface of the boolit and its ability to take and hold the rifling cleanly and firmly without leaks or damage. Interestingly, that's the secret of copper-jacketed velocity and accuracy too.

That is not the "secret". If it was then how come the RPM threshold is the same for the same bullet in 10,12 and 14" twist rifles yet the velocities are not? How is it I shoot 2600+ fps with 1 1/2 moa accuracy out of the 14" twist but not out of the 10 or 12" twist? I have measured the pressure of the same load in all 3 barrels and there is no difference. Also the holes in 100 and 200 yard targets are thesame, you can't tell which rifle they were shot out of. If the bullets weren't holding the rifling of each twist such would not be the case. The only difference is the amount of RPM.

All 3 rifles will shoot that bullet at the same RPM with equal accuracy. However, they will not do so with the same velocity. The 12" twist has a higher RPM and less accuracy than the 14" twist. The 10" twist has a higher RPM than the 12" and the 14" twists and has worse accuracy than both. I can show you the exact same difference betwe 7, 9, 12 and 14" twists in .223s. I can show you the exact same difference in 9, 10 and 12" twist 6mms. I can show yout the exact same difference in 7.8 and 10" twist 6.5s......The only difference, given the same velocity in each, will be the amount of RPM.

It is the laws of physics and ballistics, they are what they are.

Larry Gibson

[Char-Gar]

The RPM threshold is applicable to PP'd cast bullets. It just happens the RPM threshold for PP'd bullets is much higher, many times higher than the possible velocity produced RPM the cartridge is capable of. Just as with regular cast bullets; you can push a linotype PP'd bullet to a much hgher velocity/RPM in an '06 than you can push a lead PP'd bullet. The difference is the PP potects the cast bullet from the adverse affects of accleration as does the harder alloy.

Larry Gibson

Before WWII a German named Von Gerlich (that could be misspelled) experimented with guns that fired projectiles at hyper-velocity but had to use smooth bore guns.

I have a relative who is a genuine rocket scientist and worked on a research program to develop a hyper-velocity electro-magnetic gun for tanks. They produced velocities well over 10,000 fps and again the barrel was smooth bore. This round would penetrate through and through any tank on the planet. The program was ditched because they could not come up with a power supply supply that could be contained within the tank shell. We talked about the project at length. It seems if you can push a projectile fast enough, it doesn't need rifling to fly true, at least at any usable range.

All of this just back up your thinking that any projectile fired in a rifled barrel has it's RPM limits. To go hyper-velocity requires a smooth bore, at least at this stage of science.

I remember shooting some 220 Swift reloads back in the late 50's and using some thin jacketed 45 grain 22 Hornet bullets. These things would never reach the target, and just fragmented/exploded down range. As near we could figure they made it about 15 or 20 yards. Again it was the RPMs on the thin jacket that did the evil deed. Once we figured out why there were no bullet holes on the target we stopped that foolishness. We keep moving the target closer and closer to the muzzle until we had 22 caliber holes.

[Larry Gibson]

Originally Posted by x101airborne.........

I shot this rifle some more this weekend. I am getting good groups at 100 yards, about 5/8 inch for 5 shots. 200 yard groups open up to around 2 inches. Wich, is doable and for a hunting rifle, is better than is necessary. Bullets hit with a good WHUMP, recoil is negligable (even for my wife who is a new shooter). I have not shot an animal yet, so that is to come. Two water jugs explode when shot but not fully penetrated the third, so for our light game, I think the alloy is just about right. I have not chrony'd these, but I am wanting information from the target, not the chrony.

Appear from the non linear expansion of the groups (assuming wind and perhaps parallax in the scope were not the cause) that that load is on the raged edge of the RPM threshold. Probably 1 or 2 shots in the group crosed the threshold and opened the group. Those types of pesky little flyers are usually the 1st indication of exceeding the RPM threshold. Be interesting to see what that load chronographs at and compute the RPM.

I shoot quite a few hunting loads that are on the raged edge at 200 yards accuracy wise, just like yours, because they are certainly adequate for hunting and 200 yards is pretty much my max range with cast bullets for hunting deer, pigs, elk, etc.....that's what I often refer to as "useable accuracy".

Larry Gibson

[felix]

Only very minor rotation is needed or hinted at, if that, in outer space. ... felix

[Larry Gibson]

I need to squeeze a question in here if I may? I have an 03-A3 that has been sporterized and I know I have not shot it too much and, my Step-dad that gave it to me didn't shoot it except for hunting season. That being said, I am wondering where to size my boolits that I am casting. They come out of the mold (and cooled for 24hrs) at .3105 +/- .0005. I am hoping that .309 will work, but needing some expert opinions. I have tried to find a .32 caliber round ball or 2 where I live and all of the shooting suppliers just look at my like I am NUTZ. (May be). I don't really want to order a box of them and use 2. I will keep looking, but just need some advice.

If the bullets are ".3105 +/- .0005" I would suggest sizing them at .310. My "go to size" for .308 cal barrels is .311 if the bullet drops that large. If under I size the bullet at minimum.

Are you wanting the .32 RBs for shooting or slugging? Suggest you look in Midway or the local gunshops and get a box of Hornady buckshot of the size you want.

Larry Gibson

[Wolfer]

Trixter
You can cast you a few boolits with pure lead in your regular mold then cut them off a little longer than caliber. If you drill a small hole down the center they go through a lot easer.
If their not quite big enough you can tap them with a hammer and bump them up.

[Larry Gibson]

Gear

Please don't tell me that the patch prevents nose slump, accordion, or damage from entering a throat crooked, because paper isn't that sturdy!

Paper is that strong, especially when compressed into the lube grooves and held there by the barrel. Simply because you do not want to believe it doesn't mean it isn't so. Seems the end result that PP'd bullets of the same bullets and alloys can be shot accurately to higher velocity/RPM should tell you it's doing something. What it's always told the rest of the shooting world is the PP is a jacket of sorts. Your own success with PP'd cast bullets should tel you that also.

Larry Gibson

[geargnasher]

Gear

Please don't tell me that the patch prevents nose slump, accordion, or damage from entering a throat crooked, because paper isn't that sturdy!

Paper is that strong, especially when compressed into the lube grooves and held there by the barrel. No. Paper "compressed" into the lube grooves does nothing. Recover some confetti sometime and show me where it does anything but just idle there in the grooves. The way that one group of "slicks" I just shot worked makes me speculate that the lube grooves might even be a detriment. Simply because you do not want to believe it doesn't mean it isn't so. True, belief has nothing to do with it, however, it is a fact that a patch doesn't support the tip of the boolit nose against deformation from launch acceleration, heck, I don't wrap clear over the nose! Seems the end result that PP'd bullets of the same bullets and alloys can be shot accurately to higher velocity/RPM should tell you it's doing something. I've been telling YOU this, Larry! :-o I know! What it's always told the rest of the shooting world is the PP is a jacket of sorts. Your own success with PP'd cast bullets should tel you that also. I *think* I know what a jacket doesn't do, the whole thing I'm trying to figure out now is just exactly what DOES do that is different from a bare boolit.

Larry Gibson

A paper jacket doesn't eliminate casting voids.

A paper jacket doesn't support the part of the nose that doesn't touch the bore.

A paper jacket will not keep a base from riveting. I can bend a paper-patched boolit with my fingers, unlike a copper-jacketed bullet, so the paper won't make up for a crooked start in the barrel.

Paper won't keep the boolit from collapsing the lube grooves, but I've yet to collapse lube grooves with any of the loads applicable to this discussion.

I'm left having to think that the paper, which is extremely strong under compression (like you said but has nothing to do with the grooves), adds tremendous strength to the bearing surfaces of the boolit. How that alone affects boolit balance in flight doesn't compute, because the barrel alone supports the bearing parts of the boolit anyway. See my confusion? The only thing I can see that a patch significantly changes vs. a plain boolit is something that shouldn't affect symmetry or boolit balance in flight. Strengthening the bearing points is the only thing I can come up with that makes them shoot that much better than an equally well-fitting plain cast boolit, but by what mechanism, I can't say.

I'm just asking for your thoughts on this, if any. I keep eliminating variables (I think) and am down to just the bearing points of the boolit being the key to HV accuracy. A gas check adds about 30-50% or so increase in accurate velocity to a plain-based, grease-groove boolit vs. a plain base of the same alloy, and a paper jacketed (without a check) can add another 40-50% or even more to that. What gives? Am I off-base attributing this to bearing surface strength? But if so, does a failure of some sort of the bearing surfaces cause the RPM threshold?

You say it's embalance due to imperfections (of any sort, voids, launch damage, acceleration damage etc.) rearing it's head above a certain RPM that causes our accurate velocity limit. I'm beginning to think it's the ability to traverse steep rifling fast without damage to the bearing surfaces that determines the accurate velocity limit, but the sort of damage it would incur (stretched engraves or partial stripping?) doesn't seem to be the sort of damage that would cause embalance in flight. Possibly uneven gas jetting at muzzle exit due to trailing edge engave leaks?

Here's an actual example of what makes me think bearing surface strength is critical to accuracy:. M70 .30-'06 (ten twist, of course) and NOE 311-165 boolit, 15 bhn ACWW +1.5% tin. Mould has both plain base and GC cavities. Accuracy with PB boolit quits right at 1600 fps. Add a check, same lube, slower powder, it's accurate to 2K fps. Take the PB boolit, size it to .302" and patch it, slow the powder again to match the velocity increase, it's accurate to over 2600 fps (I never tested it faster, it showed no signs of accuracy failure at that point). What gives?

Here's a pic of some .30 caliber boolits that I shot the other day. Look at that long, skinny nose! They tested at 13 bhn the day I shot them at 2724 fps! I can't wait to shoot them at longer ranges and see how the group dispersion holds up. If the noses are slumping significantly, though, they're doing it without affecting the balance or else how could they shoot a 3/8" group at 50 yards? What about that cupped base, and no filler, with only a folded, wrinkled layer of paper to protect the base edges from damage? If these boolits shoot well at 100 and 200 yards we will have to seriously review some of our theories.

http://castboolits.gunloads.com/imagehosting/thum_89094f36dc69b1d42.jpg (http://castboolits.gunloads.com/vbimghost.php?do=displayimg&imgid=3910)

Gear

[tgator]

Not meaning to barge in, but the question came to mind that perhaps the paper insulates the outside of the boolit from microscopic burrs or imperfections of the rifle bore. We all know that steel cannot have a surface as smooth as harder materials and as such will have flaws that may
tear tiny chunks out of the bands or surface of the boolit that lube cannot protect. It also works as a much better "O" ring to seal gasses in the bore.

Tim

[Reload3006]

I have to say that I am of the persuasion that you can indeed over stabilize a bullet per-se. If you have a perfect bullet perfect in every respect you cannot over stabilize it the only issue would be the imperfections imparted by the rifle bore. Then you don't have a perfect bullet anymore. we know that centrifugal force acts upon our projectiles and imbalances however minuet causes Yaw this yaw can cause unpredictable deviations in impact point. somewhere we hope to find the appropriate sweet spot that the yaw is in tolerable parameters hence we all know the Greenhill formula too slow a rotation we don't get adequate stabilization. In a perfect world we wouldn't have to worry about spinning to fast or "Over stabilization" but this is not a perfect world and there is no such thing as a perfect projectile even if it was manufactured Perfectly it would be rendered imperfect upon firing. So I agree in principle with the spinning to fast affecting accuracy ... then again its all really theory anyway.

[Larry Gibson]

Gear

Take an objective look at your own PP'd bullets. The nose is very short, not a long bore rider, and matches the description I give to a "properly designed cast bullet" for HV to push the RPM threshold. There are no lube grooves to collapse nor will there be any area for the rifling to chip off any part of driving bands. The bearing surface is 3/4 to 7/8 of the bullets length (again a design feature for the best HV cast bullet). The bases of the bullet are square and flat (again a design feature of the best HV cast bullet).

Yes paper is relatively soft when flapping in the breeze. However, when tightly compressed between the bullet and the barrel surface it will be very, very hard. If you've recovered any after being shot you will note the very hard and often times brittle nature of the "after" PP is much different than the "before" paper. Even on cast bullets with lube groove the PP does fill in and support the lube grooves so they do not collapse. The PP also reduces to zero the friction of the alloy against the barrel. With a regular cast bullet this also is a great inducement (kind of like pulling back) to the alloy to slough or set back into the lube grooves. As tgator mentions the PP also insulates the bullet alloy from the imperfections and fouling in the bore which can cause imablances in a regular cast bullet.

The PP probably is a much better seal to prevent any or all gas blowby, especially at the higher psi needed for HV, and the PP also insulates the cast bullet from the heat generated by friction. The PP prevents all those things that act to imbalance a regualr cast bullet.

Point is, even the PP'd bullet will have an RPM threshold because at some velocity/acceleration level even the nose of your PP'd bullet will slump or you may ritet the base. The hardness of the alloy and the acceleration rate will determine the point for that. However, you may not have the case capacity to reach that level of velocity/accleration. You could go to a faster powder and maintain the same max psi and increase the acceleration rate but the velocity would be lower. Accuracy would fall off at a much lower velocity then as you would/could find the RPM threshold for that combination of components and rifle.

The RPM threshold of 120 - 140,000 RPM is for regular cast bullets as I have said so many times. You are trying to fit a PP'd cast bullet into that criteria and it doesn't fit because it is not a regular cast bullet used as such. Even the regular cast bullet is not the same as it is not encased in anything but is lubed, GC'd and shot as its. Because the PP'd bullet doesn't fit into the regular cast bullet RPM threshold does not mean the PP'd bullet doesn't have an RPM threshold of it's own. It does as even jacketed bullets do. You need to understand their RPM thresholds are much higher is all because they are different with the PP. This is why you are able to drive them to higher velocity with accuracy because you not hit the RPM threshold for them yet. You are not understanding about the difference because you are trying to put the proverbial square peg in the round hole. Accept the regualr cast bullet for what it is and the PP'd cast bullet for what it is and then perhaps you'll understand there is a difference.

Larry Gibson

[geargnasher]

I'm sure the paper jacket does have an accurate velocity limit, but with slow powder it's at least as high as the capabilities of the .30-'06 which is plenty for me!

I see where you're thinking I'm attempting to "fit a square peg in a round hole", or it could be said comparing apples to oranges, but in the case of the RD 30-165 I was using the paper patch as just one more tool (like a gas check or alloy change) and observing the effects. I'm just about convinced the difference is in the bearing surface support.

What you said about the paper/barrel interface and friction turned on a lightbulb. I know a patched boolit has a great deal less friction with the bore than a regular boolit, and that paper is more resilient than even the best lead alloy under compression, so it acts as a sabot of sorts to deliver the boolit out of the gun without subjecting it to the vagaries of direct contact with imperfect rifling.

So, I think I'm finally getting my answer to HV cast boolits. If bearing surface damage is the cause of the accurate velocity limitations after nose/base/casting issues have been resolved, there's really not much that can be done to improve things other than a harder alloy and addition of a compacting, sealing filler behind the boolit, which in effect accomplishes the same things (gas seal and higher resistance to bearing surface damage) as a patch.

I'm still muddy on exactly what happens to the bearing surfaces that cause this "RPM threshold", if indeed bearing surface is the cause. Seems to me anything the lands could do to the boolit wouldn't affect balance that much, which in turn makes me think it isn't so much a balance issue as has been thought.

Gear

[Larry Gibson]

I'm still muddy on exactly what happens to the bearing surfaces that cause this "RPM threshold", if indeed bearing surface is the cause. Seems to me anything the lands could do to the boolit wouldn't affect balance that much, which in turn makes me think it isn't so much a balance issue as has been thought.

Fact is it doesn't take much to imbalance a bullet. Any imbalance to any bullet will cause inaccuracy. Check with the benchresters, jacketed and cast, if you don't think so. Also check with any ballistician. I've explained this so many times.....[smilie=b::groner: but I'll give it another try with you because I like you:grin:

The RPM threshold is that point in which the centrafugal force caused by RPM overcomes the stability of the bullet to stay on the intended flight path (can be an accurate one or an inaccurate one). The bullet at that point then begins a helical spiral which gets larger as the range increases (non linear expansion of groups at farther ranges) or the bullet departs on a complete tangent to the flight path. This is not to say the bullet loses stability as it most often doesn't and still flies point forward even though it is off the flight path. The centrifugal force from the RPM is just pushing the bullet into a new flight path diverging from the original flight path.

The unbalancing of the bullet occurs during the internal ballistic phase while the bullet is constrained by the barrel. The adverse affect of the RPM/centrafugal force on the unbalanced bullet occurs during the external ballistic phase when the bullet is in flight and is unconstrained by the barrel. The adverse affect of the RPM threshold/centrafugal force does not occur in the barrel but outside of the barrel. With regular cast bullets in CF cartridges using the slower fast burning powders through the slower medium burning powders the RPM threshold generally falls within 120,000 - 140,000 RPM. It is entirely posible to lower the RPM threshold and to raise the RPM threshold ("push it" as I call it). I have discussed how to do either numerous times.

What occurs is not my threory, it occurs because of the laws of physics and ballistics. That's how it is.

Larry Gibson

[Dthunter]

I think you guys need to read Brian Litz book on the phisics of bullet flight for long range shooting.

It "MAY" shed some light to the forces of physics that a bullet experiences.
Its quite interesting.

Remember guys, keep an open mind, that is
The "ONLY" way we can learn and move forward.

Keep it fun guys!

[x101airborne]

Well, If I ever wanted to prove anyone right about bullet twist and over/under stabilization, I think I have just done it. Mr. Larry Gibson, once again, hats off.

Yesterday I went to the range to shoot some of these rounds at different distances with some different modifications to each load. All this was shot off a well grounded bench with front and rear sandbags. At 100 yards, I am getting nice, round, consistent 1/2 to 3/4 inch 5 shot groups. But that is not the surprising part.

At 200 yards, My groups are opening up to about 2 1/2 inches and are landing 5 inches to the right! Talk about a curve ball! Not to mention that my rounds are dropping almost 18 inches at that distance, wich for me will be the game limit of my shooting with this round, apparently. To zero the rifle for 200 yards, I am shooting almost 3 inches left at 100 yards. Well, if that doesn't prove the theory of over stabilization induced by spin and bullet shape in a 1-10 twist barrel, I dont know how one would. Now I just really need to remember my chrony next time.

[Char-Gar]

x101... You post recalled to my mind the old Buffington rear sight on later Trapdoor Springfield 45-70 rifles. To sight was build to compensate for the bullets rotational drift as the ranges extended. If you look at the elevation staff of one, it is plain as day.

[x101airborne]

I had no idea that spindrift would be so bad at a relatively short range. Never woulda guessed it.

[x101airborne]

But ya know..... The more I think about my results this weekend and what Larry and Gear have been trying to tell me........ Yes, the spindrift is a symptom caused by a lack of velocity and an over rotational condition. If velocity is directly relative to spin (and vice-versa), shape and weight to give the boolit stability and alloy to overcome centrifugal forces of spin and acceleration, I feel that is the short version of relationships between weapon and boolit. And as far as I can think right now, it seems to hold true in handguns, rifles, and shotguns.

So applying this THEORY to my own situation, with my spindrift results, I will need to do one or a combination of several things to alleviate this situation.
First..... I could use a slower twist barrel. Expensive, but possible.
Second.... I could push a harder alloy faster. But would negate expansion.
Third.... I could use a softnose boolit with a real hard base and push it. Wich is what I am already doing by the Beartooth method.

Anyone got any other suggestions? I really need to knock down this spin thing.

[Char-Gar]

I would suppose you would find a solution in your list of possible things to do. However, I am a simple sort of fellow. I would just find a load that groups best, shoot it over the various ranges and determine the amount of drift and adjust my sights for the range.

We do this for windage and elevation, why not add drift to the adjustment list? At the end of the day, no amount of load fiddling will replace basic riflecraft.

When we drop the velocites of a bullet to usual cast bullet speeds, we encounter all sorts of interesting things that the high velocity guys never run into. That is what makes this stuff so interesting.

I wish you all the best in your shooting and life in general.

[popper]

Spin drift is a wind and gravity thing, precession on a gyro. Also causes a nutating helical path. There is a calculator for someplace - forget where. Over-spinning a bullet can only cause it to come apart when alloy strength is exceeded. Force on the base is converted to forward and rotational force - too much spin and forward speed is less. Force on base must be behind COG or it will tumble. As the front and base of bullet start with different rotationally velocity, material weakness may allow it to get twisted, meaning weaker CB. Paper is quit strong in certain circumstances. Also consider that it may act like the rotating bands on artillery shells, forget what they are called. It could allow rotating slip before the whole CB is rotating so the CB is not weakened. Could be a combination of the above and what gear and larry said.

[Char-Gar]

Popper...If you are going to post in tounges, take it over the The Pit where religious material belongs. :-)

[nanuk]

some thoughts came to mind after reading Reload3006's post 121:

using a gyro top as an example, if spun Very fast, it not only rotates and stands up, but yaws around the axis, until it slows down some, then spins true for a bit. Same as the Earth. Could this be why the CM in the Swede hits the target in a Yawed state, routinely?

Larry's comments about alloy strength and velocity has some interesting theory going on. BUT, again, if the Rifling CUTS the paper in the bore, the barrel HAS TO contact lead on the side of the boolit that is forced into the rifling. (am I wrong here? isn't this why we want to see confetti? the boolit is bumped enough to CUT the patch?)

but I do see the trend of the better bearing surface, the higher the RPM/Velocity that can be attained ( with accuracy )

[nanuk]

Gear---you said:
“The 720 factor is your feet converted to inches (so you have a common denominator with the twist rate in the next operation), then multiplied by 60 to convert it to "minutes", again to yield an answer in "rounds per minute".

Did you mean "revolutions per minute"?


Yes. :killingpc

Gear



If I may be so bold... Rotation??? revolution implies going around something. Rotation implies spinning??

[Silvercreek Farmer]

If I may be so bold... Rotation??? revolution implies going around something. Rotation implies spinning??

A bullet would revolve around its own axis.