Making the most of a good rifle

[btroj]

Ok, this is my follow on to Tim's thread on twist rate.

What dos it take to make the most of a well made rifle?

What is fit? It is way more than getting the bullet the right size to seal the bore.

What does it take to make straight ammo?

How to cast the best possible bullets, size them without deforming them?

How to load ammo so we don't damage the bullet as it leaves the case, enters the throat, and travels the length of the barrel.

Seems to me that after the gunsmith does his best to make a rifle capable of good accuracy that we need to know how to make the most of it.

I would like to keep egos out of this. What do YOU do to make the most of an accurate cast bullet rifle?

[johnson1942]

read every thing you can about harry pope. alot of what you want, he did,and still applies to day.

[btroj]

Rick, think some of that is because an inside reamer follows what is already there. Outside turning makes the entire necks consistent thickness, inside reaming does not.

The BR guys outside turn and I see no reason to not follow their lead on this one.

I think inside reaming was "the thing" before outside turning hit the scene. Once outside turning was discovered and became popular the vast improvement made it the norm.

I wonder how outside turning would work if the neck was held in a die at the time? The wall variations would then be forced to the inside and could be removed. Don't know?

Rick, it is experiences like the one you mentioned that stick with us forever. The kind of failure just never leaves us.

Great point as a bolt action pistol for silhouette isn't any different than shooting a rifle. Revolvers are an entirely different beast.

I fell I to the neck turning fad when I got my 22-250. Man, I was gonna make it shoot better than anyone else. Neck turning didn't do anything except give me blisters. It did lead me into shooting Highpower and that, along with a subscription to Precision shooting, taught me lots about making good ammo and how to shoot.

Tim was a bit amazed at the dies I sent him for modification for my rifle. A Redding bushing FL sizer and a Forster Ultra Seater with the micrometer top. If those don't keep my cases and loaded round straight I don't know what will. The bushing die also allows me to control neck tension without using an expander other than to slightly bell the mouth to prevent scraping the sides of the bullet.

I learned that lesson from shooting poor groups with my AR at 200. It just didn't group like I wanted. Tried a fellow shooters runout gauge and about died. My Hornady dies were giving me .007 to .009 runout for loaded rounds. The cases as fired from the chamber showed .001 or so on the neck. Dies were making my straight neck crooked. Got Redding and Forster dies and that went away, groups tightened, score went up.

[btroj]

Yep, following a hole that isn't centered just makes a different size hole that is off centered.

I think this new rifle will teach me a bunch of stuff. If nothing else it will be a harsh judge of my bullet and load quality.

I did learn a bunch shooting Highpower. I learned to get the right tools for one thing. A Wilson trimmer, Bushing dies, a good seating die. A concentricity gauge was a real eye opener. What I thought was good ammo turned out to really suck. Explained some targets.

Amazing what we learn when every shot counts.

[btroj]

I still size a few in my Lyman but that will end soon. I need a few more dies for the Star. Push thru like that is the only way to go. Heck, I can see it on the sides of the bullet when one side is sized more than the other, a lot more.

We can make bullets worse in sizing.

[357maximum]

Ignorantly going forth not knowing what was "impossible",
Proper fit (gently engage the rifling or fill the throat...or both),
proper alloy for the task at hand,
proper powder burn rate selection,
sizing nose first via the STAR or Lee systems,
and letting it all hang loose via the floating dies in my Co-AX
...are proably the best things I did for accuracy other than learning how to cast good consistent boolits.

[btroj]

Ok Mike, please tell more on powder selection. What did you do and why? I have a hunch but others may not.

The work you guys in Michigan did with the Cu addition to the alloy is a huge contribution. I wonder how much faster we can shoot bullets now? Bet it makes a big difference.

Please tell more.

Oh, you forgot to mention how steep that hill was as you climbed it. It always seems to get steeper.

[btroj]

True. Speed is fine for mass produced ammo but for the good stuff speed isn't important. Better 10 good ones than 100 ok ones.

My star doesn't have a set screw for the die. The lock nut is long since lost. I haven't tried the method you mention with holding the bullet until the punch makes contact and letting it find center better.

Now that it what I want to know. Never thought of that but it sure makes sense.

Similar to the lost lock nut on the Star punch I have used a large O-ring under the lock rings on my dies in the press. It lets them float just a tiny bit and I found it helped me get straighter ammo. Amazing what I learned in a book about making good ammo.

[357maximum]

Brad

MATCH THE HATCH...it is a fishing term I know, but it applies to powder. Shorter barrels like faster powders and/or heavier boolits. Long barrels can use the opposite, but may not REQUIRE it. Dutch4122 was the one who really clued me in to the "muzzle pressure" thing via some HOOOOOOOOOOOOOTTTTTTTTTT Noisy Maggot rounds...it helped alot and I am forever in his debt.


The CU enhancement thing helps in keeping a useable hunting boolit at velocity, but you cannot put a spire on a building that does not exist.


Actually the hill was not that steep at first....my first casting sessions were done by pure happenstance with what I believe were copper laden alloys, as I noticed alot of familiar traits once BadgerEdd and Babore pointed the way in that arena. I guess that having good and knowledgeable shooting buddies should have been first on my previous list......bad omission on my part there. :drinks:

[357maximum]

Another thing I do with the Star is leave the punch nut off, just don't use it. Leave the punch to free float. I don't use the die set screw either. Don't drop the boolit into the die, with the arm raised loosely hold the boolit base up against the punch and lower the punch allowing the boolit to find center of the die without loosing contact between the punch & boolit and then push it thru. That's as straight as you can get the boolit into the die.

Yes, there are faster methods including boolit feeders but your not trying to see how fast you can shoot groups, your trying to shoot good groups and a straight, concentric boolit is a good place to start.
Rick


It's funny you mention that as the less I try to aligne things mechanically and just let them do it themselves the better things are.......hence the STAR and the CO-AX. I use the stop nut on my star, but I use it as an index only. I bring it tight and back off a 1/2 turn, that is how I use it...my base punch is never "tight" in use. I will never have a boolit feeder on my STAR, just do not see the need. I can already do a 4 hour casting session in 20 minutes....what's the point in shaving part of 20 minutes off?

[btroj]

Yes, good friends who know their stuff makes it all easier. Amazing what happens when guys put their heads together, work on a problem, and get it hashed out.

I have learned that powders seem to have a range of velocities where they work well in many cartridges. Get outside that velocity window and they just aren't a good choice. I like 2400 but I stop using it if I want a rifle bullet outside the 1650 to 1850 fps window. Well, most rifle bullets, it depends on the cartridge.

[btroj]

It's funny you mention that as the less I try to aligne things mechanically and just let them do it themselves the better things are.......hence the STAR and the CO-AX. I use the stop nut on my star, but I use it as an index only. I bring it tight and back off a 1/2 turn, that is how I use it...my base punch is never "tight" in use. I will never have a boolit feeder on my STAR, just do not see the need. I can already do a 4 hour casting session in 20 minutes....what's the point in shaving part of 20 minutes off?

I don't have a feeder either, I just don't see a need. My arm gives out fast enough already. I do this for fun, not production.

Maybe that is why I use a Dillon 550 and not a 1050 with a case and bullet feeder?

[357maximum]

Next we can talk about completely flat gas checks snug against the boolit and square to the boolit.

Rick


I stressed over this for a long time. With proper moulds or moulds that have been properly lapped out in that area until they are right..... and using the STAR I have not seen it be an issue. Using moulds with too fat a gc shank should be about the only issue here, and I have not positively proven to myself that gas checks do not seat themselves pretty well when forces equal to 20 to 60 thousand pounds per square inch are placed against the properly cast boolits butt.

[btroj]

Ok, I see it now.

A guy we need to show up here is Ben. He always has interesting ideas. That has check seater he had Buckshot make for him is a great idea. Check always goes on square and bullet is held firm so it can't go anywhere.

What is your method for getting checks square and flat Rick? Do you ever anneal your checks?

[btroj]

I stressed over this for a long time. With proper moulds or moulds that have been properly lapped out in that area until they are right..... and using the STAR I have not seen it be an issue. Using moulds with too fat a gc shank should be about the only issue here, and I have not positively proven to myself that gas checks do not seat themselves pretty well when forces equal to 20 to 60 thousand pounds per square inch are placed against the properly cast boolits butt.

Never though of it that way. The pressure of the powder burning is likely to make the check go square. Problem is how do we know for sure? I like to know rather than assume although in this case we are likely ok.

What says Rick?

[357maximum]

Brad


I had Buckshot make me shell holder/snap in a gascheck seater years ago...it is in my parts drawer someplace. Once I got away from the lyman in/out sizing operation it no longer seemed needed.

BTW....My list above should of had consistent neck tension and the preferred neck tension for THAT RIFLE near the top. I spent most the afternoon beating on paper/steel through a scope and my eye's and brain are not in concert right the moment I guess. I finally succeeded in getting mydead stock 14 inch 30/30 contender sub-inch @100 with a Saeco 316 load approaching or just a tick beyond 2K...woohoo for me.

[357maximum]

Never though of it that way. The pressure of the powder burning is likely to make the check go square. Problem is how do we know for sure? I like to know rather than assume although in this case we are likely ok.

What says Rick?


Just remember....I did not say I haphazardly toss a check on there, but I did quit stressing over it. Of all the variables I have played with this one is near the bottom if the shank is right in the first place IMHO.

[btroj]

I had a Lee 45 300 mould for 45 Colt that had a huge check shank. It was a bear to get a check anywhere near square on that sucker. Luckily I decided that mould didn't fit my needs anymore and I gave it away. I have been fortunate to have most moulds give a good snap on fit with checks. I call it luck.

Neck tension is a big deal. Too much isn't any better than too little. Key is finding just right.

[357maximum]

I had a Lee 45 300 mould for 45 Colt that had a huge check shank. It was a bear to get a check anywhere near square on that sucker. Luckily I decided that mould didn't fit my needs anymore and I gave it away. I have been fortunate to have most moulds give a good snap on fit with checks. I call it luck.

Neck tension is a big deal. Too much isn't any better than too little. Key is finding just right.


CASE IN POINT.

I have a 35WHelen sporter on an old 98mauser. That gun will shoot 3/4 - inch or so groups at 100 with freshly annealed brass @ 24-2650 fps. It wants it's brass annealed every time the case is re-stuffed however. If you do not the groups will grow to 2 inches on the next firing, and out to about 2.5 the next firing if not annealed.

My 357MAX 15 inch MGM Encore is the exact opposite, it does not shoot worth a hoot with annealed brass, that gun wants all the "neck" tension it can get with it's preferred deer shmuckin load. I compromised and "neck" size the brass for that gun with a 38acp sizer (thanks Bob) as it gives just enough case tension without the "snake that ate and egg" neck that a standard max die will give you.

[btroj]

Now THAT is the kind of info we need. I do know many BPCR guys like to anneal cases every load.

Like Bass used to say- it only matters when it does.

I know that snake ate an egg case look. My 45 Colt loads pretty much always look like that. I started sizing just enough case to hold the bullet snug, I hope it reduces case loss. To when those cases split it is almost the full length of the case.

[btroj]

Wow, that would be a pain. Like you said though, when the shots count is there such a thing as too careful?

I have never annealed checks but have considered it. Might try it and see if I can tell any difference. I hate extra steps that have questionable value.

[geargnasher]

CONSISTENT neck tension is paramount. Inconsistencies here can show up as stringing and be attributed mistakenly to other issues.

As for gas check seating, the check should be snug on the shank and the boolit base should be solid and square under the check. I have long held that if the boolit base is good, the bump in the butt at firing will marry check and boolit quite handily, the trick is of course to make certain that the marriage is a square and well supported one.

Here's what, so far in my bumbling journey, I have found helps accuracy, PARTICULARLY at higher velocity:

Numero Uno: Static and Dynamic fit. This has been covered many times. I used to think the nose had to engrave, and sometimes it does help, but if every process of building the cartridge is done in a concentric manner and tolerances are reduced to the absolute minimum required for function (brass AND boolit), then the nose doesn't need to "engrave" because it has nowhere to go but straight. There are lots of little details to this that most people miss. I'm sure I'm still missing a few in general.

Numero Dos: Balance the primer, powder charge, powder type, and alloy to the job at hand.

Numero Tres: Make sure you have a rifle capable of shooting well (decent bore condition, bedding, crown, straight chamber, etc). Maybe that should be the FIRST thing, but I started this list assuming the rifle is good.

Numero Quatro: Learn how to shoot.

Here's the .30 XCB (L to R) with a junk case used for an OAL test fit, a ragged chamber cast (throat is smooth as glass, this was a Mulligan, note two sets of rifling marks), and a ready-to-shoot loaded cartridge:

http://i1328.photobucket.com/albums/w538/Geargnasher/100_4069_zps297c33df.jpg (http://s1328.photobucket.com/user/Geargnasher/media/100_4069_zps297c33df.jpg.html)

Gear

[btroj]

How often do you plan to anneal those cases Gear? I figure that they will need it every 5 loads or so. Then again with a snug throat, turned necks, and a sizer that doesn't over size they won't work harden as fast due to being worked less. Might never need annealing or maybe after 10 to 15 loads.

Shot any of the new bullet yet? I bet it works well. Love that contact with the rifling. Between that and turned necks and a tight neck chamber that bullet can't help but go straight. Just be gentle on ignition. I plan to use RE 19 to start. I have some old AA3100 I can try too if needed.

[357maximum]

I tried annealing on several toys, but once I got some moulds in my hand that were "right" I quit doing it. I would rather have a slightly loose check/shank fit than an overly tight one...Rick just reinforced my thinking on that.

I watched Dutch4122 shooting a model 71 in 348 one day down in S. Illinois. He was shooting pretty darn good, but I kept noticing something flying and hittin about 20 yards in front and slightly off to the right. His checks were actually coming off consistently and for a reason I cannot remember now(old lyman checks maybe)???, but the boolits were making a pretty good group. His gas checks had about a 6inch group going on the ground out in front of us. :lol:

My shooting is never ever going to "totally ruined" by a flyer that lands 1/4 inch out of the group, still bugs me if it happens, but my steel plates and the venison simply do not care. Rick is talking a whole other level of "playing" than what I am normally up to.....might want to listen if he thinks it is worth the effort he just described.

[357maximum]

Gear

Your cartridge on the left is what I normally strive for in a rifle/specialty pistol, but in some guns it simply is not possible. Barring that light "engraving" "engagement" up there I try to get similar marks on the first drive band, or in some guns a simple throat ring around the boolit....all seem to work in their respective instances. It is really nice when you can get both types though.

[btroj]

Those silhouette guys get pretty riled up over misses......

Anyone else ever notice that loads that are really bad and over the top for the alloy tend to throw a grey cloud in front of the muzzle? I can tell right away when loads aren't gonna be on paper. The bullets are stripping from the rifling or something. Odd thing is that some of these loads didn't lead! Accuracy was minute of truck or so at 100 but no leading. Must have been my superior lube!

I agree that checks are better a bit loose than tight. Sizing will snug up a check some but I like to make sure they are on straight as possible. I will try to avoid using a rubber mallet, that is a bit too much work.

[btroj]

Gear

Your cartridge on the left is what I normally strive for in a rifle/specialty pistol, but in some guns it simply is not possible. Barring that light "engraving" "engagement" up there I try to get similar marks on the first drive band, or in some guns a simple throat ring around the boolit....all seem to work in their respective instances. It is really nice when you can get both types though.

That fit isn't by accident. A really good reamer and chamber mated with a great custom mould made to fit that specific chamber and throat. Once I get my rifle I will be seeing if my mould makes bullets that fit that well.

Speaking of bullets, how long do you guys like to let them age before shooting them? I like a month at least, 2 months is better. I want to cast a thousand or so for the new rifle initially and then try to keep well ahead.

[geargnasher]

Anneal cases? What's that? :kidding:

I'm still in the habit of using the hardest necks I can get and maybe draw them after a few firings in a lead pot (thanks Bob!) IF I have a hard time grouping them Goldilocks method by seating pressure. If I get more than three distinct piles to shoot for groups, it's time for a draw, otherwise the targets tell me, usually before I'm sure at the press. The hard neck habit was picked up when questing for tiny groups alone at average velocities in rifles where snug neck fit wasn't reasonably attainable. Hard necks and a zero-clearance case mouth flare (per Dutchman) helped me snug groups a bunch at mild pressures and with SLOOOOOOW-peaking powders in three different rifles with sloppy chamber necks. At high velocity, the hard necks alone don't cut it but are working ok with tight fit, but I may try drawing them at some point and see what happens in THIS rifle.

My .308 is grouping just over an inch repeatably at 169K rpm with brass that has NEVER had the necks annealed, not even when originally produced. Maybe IT would be a good candidate for an anneal to see what happens, since I've finally got it shooting very consistently at least. Without changing alloy (using 50/50 WQ + 1% tin, 19-20 bhn), treating the necks may be a big improvement. Neck clearance is running right at half a thousandth. Shooting this short-barreled buggar with slow powders may be another hickey, I never went faster than H414 and the muzzle pressure thing may be getting me a bit, too.

Gear

[357maximum]

That fit isn't by accident. .


I realize that Brad, but even in over the counter guns that fit is possible if one is willing to shell out the dough for the mould (A.K.A Tom@ACCURATE) and play with alloy/casting tempo/temp/nose sizing, etc, etc, etc. When my MGM 357 MAX was brand spanky new I actually had 3 points of contact. The way I have (mis) treated that poor barrel has reduced that fit to one point of contact, but she still shoot better than most.

[357maximum]

Speaking of bullets, how long do you guys like to let them age before shooting them? I like a month at least, 2 months is better. I want to cast a thousand or so for the new rifle initially and then try to keep well ahead.


I normally like at least a month or two, but that's another "IT DOESN'T MATTER TILL IT DOES" thing. With my HV toys I try to keep a supply that is 1yr old+, but sometimes I fail at that goal. My 30 Badger, 30/30, and 38 special and other plinkers made with softer mixes I have shot them so soon they were carrying residual warmth from the pot. :lol:

[btroj]

Tom is the man. I regret that I never got a mould from BaBore. I always intended too but just seemed to make it happen.

I learned much about fit in the past year. I used to think it meant the bullet diameter was correct for the bore. Boy was I fooling myself.

Fit is a many factored thing. I bought a mould from Tom for my 375. It has the check at the base of the neck with the nose in contact with the throat. The bullet is held at each end at ignition, this helps keep it going straight. I also learned to use some neck flair to help center the neck in the chamber, a 375 was never intended to be tight necked! Using a powder on the slow side to prevent any riveting of the bullet into unsupported areas on the neck or throat help keep my delicate little bullet in the same shape it started.

Yep, I used to think fit was a simple thing. Boy what a fool I was

[357maximum]

Some of the shoot-off targets in Master Class revolver open sight are about the size of a pack of cigarettes. They are at 200 meters.


Rick


If that is offhand I am screwed even if I had the best revolver on the planet in my hands. Give me a rest with a rifle or a specialty pistol and I would feel pretty good though. I like shooting golf balls @ a hunnert, but I require a rest for that. I am never gonna be that steady with that green bottle in my hand.

[btroj]

Laying his back, pistol along side of leg. Looks akward to me but the groups those guys get is unreal.

So Rick, how many older guys shot silhouette? I gotta believe that at some point just getting into position then back up got tough. The body just isn't the same as we get older, or at least that is what my knees say.

Confidence in equipment. That is a huge factor. Knowing that a shot out is your fault and not the ammo or gun is a bit factor in learning to shoot well. Knowing it was you leads you to learn WHY it went out and how to prevent it in the future. Poor ammo or a poor gun just hold you back from learning. Might be why the high masters rebarrel sooner than the marksmen.

[geargnasher]

Gear

Your cartridge on the left is what I normally strive for in a rifle/specialty pistol, but in some guns it simply is not possible. Barring that light "engraving" "engagement" up there I try to get similar marks on the first drive band, or in some guns a simple throat ring around the boolit....all seem to work in their respective instances. It is really nice when you can get both types though.

I know the feeling of wracking the brain trying to figure out how the holy heck to get something to fit when the gun isn't compatible with available components. One reason I threw in the towel and started messing with the 7mm-08 (make proper brass from '06) and finally got on the XCB bandwagon. I probably seated those a bit long, but who knows, haven't put them on paper yet. I have a few hunnert downrange with a slightly different mould that doesn't fit as well and got it consistent at 5/8" and mid 2300s (easy 12" twist).

Talk to me more about how you get away with a little bit of throat ring, that always made mine lead a bit unless I opened the throat entrance a bit for mo' bigger, neck-filling boolits.

Gear

[geargnasher]

Brad, spend some quality time hand-starting boolits into throats and pounding them out again and you get a really good concept of how to strive for a powder burn rate/alloy combo that will at least shove the gas check flush with the throat entrance before the pressure rises enough to rivet the base.

Gear

[btroj]

Brad, spend some quality time hand-starting boolits into throats and pounding them out again and you get a really good concept of how to strive for a powder burn rate/alloy combo that will at least shove the gas check flush with the throat entrance before the pressure rises enough to rivet the base.

Gear

I saw that post. Interesting to see how easy it is to rivet the bullet while getting it I to the bore.

Makes filing the throat and neck with bullet and case pretty important, doesn't it? Give lead a place to go and it will go there when under pressure.

[geargnasher]

Mike, this is a good shot of a throat ring like I think you were referring to, boolit in the middle. One on the right was sized just under throat entrance diameter before hand-seating to check contact:

http://castboolits.gunloads.com/attachment.php?attachmentid=101737&stc=1&thumb=1&d=1396929239

Brad, yeah, shootin' putty. Don't tell Richard Lee.

Gear

[357maximum]

Talk to me more about how you get away with a little bit of throat ring, that always made mine lead a bit unless I opened the throat entrance a bit for mo' bigger, neck-filling boolits.

Gear

With Super Secret Squirrel Lube of course :lol:

Actually what works for me in that really kinda rare circumstance is chemistry defeating physics....I.E. a proper TOUGH/MALLABLE alloy.......one that has at least 4 components from the periodic table in it. Terinary alloys need not apply here without a paper wrapping. :drinks:

[runfiverun]

I use a nice shiney slug on my stars to seat gas checks.
I get to feel them slide into place and feel them bottom out.

[btroj]

Ah, the old copper alloy again. I really need to try that in my new rifle. I think it will be a good thing. Sure won't hurt anything.

[357maximum]

:mrgreen: No, that's Creedmoor position. Off hand shoot-offs use the full size targets at 150 or 200 meters, Match Directors option. I make no claims to being a particularly good off-hand shooter, just was never able to get my body to cooperate and stop wiggling around. :-(

Rick


I would still be screwed, I ain't no freaking contortionist :mrgreen:

Give me prone and a long barreled single shot pistol please. :drinks:

[357maximum]

Proper alloy will make the slug in question shoot right nicely Ian, will be as good as it could be...well no, but it is better.

[btroj]

I would still be screwed, I ain't no freaking contortionist :mrgreen:

Give me prone and a long barreled single shot pistol please. :drinks:

With a bipod if possible. My 15 inch 309 JDJ is scary accurate but damn it is hard on my elbows. Gun goes up, elbows go down. Elbow pads help but it still gets my attention. There is sometime invigorating about a 165 at 2400 fps from a handgun.

[357maximum]

The bipod thing was a given...or so I thought. My favorite way to shoot a specialty pistol is prone off from a bipod.

I use a 1/2 sand bag made from an old shot bag but only loosely/partially filled with lizard bedding (aka walnut hull media) under my right elbow...helps more than a pad methinks anyway. Helps with both the skid back and with the torque.

[geargnasher]

Thanks, Mike, I figured a greasier, tougher alloy might have something to do with it. Big difference between ww and 50/50 along those same lines but one step down, the hardened 50/50 squirts through a tight throat with less shaving and objection than straight WW, and fewer debris sloughed off to get smeared into the corners of the grooves.

Gear

[357maximum]

Ian...a little supposisition on my part but here it is:

....and that's why I think Wd'ed 50/50 works so well in leverguns....enhance that same alloy with a bit of rr babbit or cu enhance rr babbit and paradise can actually be found on a consistent basis.

[357maximum]

If Tim can do it so can you. :mrgreen: A couple of weeks ago we were at a shoot in Clarksville, AR and he said he wanted to try Creedmoor so I handed him my XP in 308, showed him how and handed him a box of 311365's. He started hitting a 50 yard plate and was giggling like a little girl. Fun times.

Prone is legal in Silhouette BUT nothing from the elbows to the hands including the gun can touch the ground or have any support. That's much more difficult than Creedmoor.

Rick

Has Tim bounced around on bulldozers/backhoes/trackhoes/trenchers for a good part of his adult life??? Not saying I could not do it, but I bet I would not like it. I have watched it done, good nuff for this worn out wretch who once was a ditchdigger in another life. In the right light i both feel like and resemble my avatar ya know. :lol:

[HollandNut]

I have found that no matter how great the rifle or components and the time spent fiddling with them , that I am still the weakest link ... The greatest components in the world can't make up for the shooters errors ..

One of my dead heroes ( Jack O'Connor ) said in his tome' 'The Hunting Rifle' something to the effect of :

"When my wibbles compensated for my wobbles or I flinched just right or something , I'd get a group smaller than 1 1/2" ( five shots ) , sometimes a good deal smaller , but I couldn't count on it ( being repeatable )"

I'll never be a MOA or sub MOA shooter with anything , and don't worry too much over it

[btroj]

Yes, the shooter is the weakest link BUT a good rifle and good ammo make it easier to learn.

Think of it this way. My rifle holds x ring, your hold 9 ring. We both shoot a 9 at 9 o'clock. I know my hold was good, I can then be assured I missed a wind change. You assume all is well and fine. I adjust and next shot is am x, you don't and your next shot is a 7 at 9 o'clock because the previous shot was actually on the right edge of your group, not the left.

See how knowing the rifle and ammo shoot well lets you have the confidence to make the change? Without a good gun and good ammo it is about impossible to learn to be a good shooter.

[HollandNut]

true dat no doubt

[Love Life]

Launch....launch....but what else? I keep seeing that sharp rifling imparting imperfections on the boolit as it travels down the barrel. Getting the bullet into the barrel unharmed is important, but what is the rifling doing to the boolit as it travels down the barrel? Is that knife edge rifling really working in your favor?

Is the sharp front drive band a good thing? Why? What I see (handguns only so may be irrelevant) is that RN and WFN with a nice taper to the ogive and bearing surface have unbroken coatings. Boolits with a sharp front drive band get broken coatings. Additionally sharp rifling CUTS into the coating. Now, I know rifles to hand guns is an apples to MRAP comparison, but rifling is rifling.

Earlier a member mention a gain twist. Why wouldn't a gain twist benefit you? Control the launch RPM. Too bad no squeeze bores are around to play with to see if reduction in diameter might swage the voids out of boolits as they travel the bore.

The wall I see is that every rifle is a law unto itself. Trying to come up with info that will allow anybody to shoot cast with REAL jacketed performance in anything from the wally world special to the bench gun is an almost impossible task.

[btroj]

Rick, that info about crimp not doing much but hold the bullet under recoil is so true. Everyone wants more crimp to improve powder burn or consistency but it just doesn't cut it. I have even used a 44 mag expander for 45 Colt ammo to improve neck tension.

Might be why I like the Redding bushing dies, it lets me determine the tension during sizing instead of using a stock size expander to do it for me.

Speaking of expanders, anyone got opinions on them?

[Love Life]

What opinions would you like on expanders? For your rifle I would be looking at a separate expander die with mandrel sized to give you the neck tension you want...or not. Just a mandrel expander and then you can use your bushing dies...

Of course with your cast boolits you will want a slight flare to allow you seat the boolit. Mebbe a custom mandrel for a M die.

[btroj]

I actually have some custom mandrels for a Sinclair expander die. They will size to an appropriate dimension and give a little belling to keep the bullets intact. They are also .002 or more larger than my M-die.

I need a longer expander die so I can easily adjust the die to control the belling and keep it consistent. Current body is too short to use it that way.

I am looking to control tension entirely with my bushings for the new rifle. Time will tell how well that works out but I have no doubt it should be good.

I need to have Buckshot make me some new expanders for other calibers. The 375 in particular.

[Love Life]

Sounds like you have what you need. Now you just have to put ammo together and start shooting...and taking notes.

Now, the real question is: Does your rainbow rifle shoot with a lisp?

Do you have quickloads? What's the slowest powder you plan to use with your rifle? What part of the powder speed spectrum do you plan to play in?

[btroj]

The rifle hasn't gotten here yet so I have no idea what she sounds like.

I do not have quickload. I have considered it but I am a cheap sort of guy.

I plan to start with RE19. It is similar to 4831 in burn rate. I have some AA3100 that is a touch slower and some I4350 if I want to go faster. If I really want to use a faster powder I have some N540 I can try.

I do know that at some point I will use some 2400 in it for lower speed loads. I will start in the 15 gr gp range there and figure to stop around 18 or so. Once I get I to the 1750 fps range I will call it good, I find that is about the faster I get with good accuracy from 2400.

And yes, notes. Lots of notes. Lots of chrono time and targets.

First thing to do once I get the file is make some cases. I have a bunch of new 06 cases just waiting to be cut down. The holder I got from Sinclair that lets me use my cordless drill for spinning cases while neck turning will save me from carpal tunnel!

[Love Life]

I've often wondered if the slow rifle powders would be the ticket. I mean 7828 and down. Yeah, you may have incomplete burn but then again accuracy my be there.

[btroj]

I'm not sure I need to go quite as slow as 7828. I think of this case as being similar to a 308. Therefore I figure that more 06 friendly powders, like the RE19, are plenty slow. Pressure should still be high enough to get a good, clean burn but will build gently enough to prevent the damage that can occur when a big pressure spike at ignition hammers the bullet out of shape.

A gentle push, not a hard shove.

[Love Life]

Wouldn't a hard shove come from the faster powders?

[btroj]

Yep. Stuff like 2400. Key is to use the 2400 for appropriate load levels. At 1750 fps the pressure is still low enough to allow decent accuracy. If I tried to go 2100 fps with 2400 the accuracy wouldn't be there, he bullets would be damaged enough on ignition to make it not worthwhile.

Trying to use a powder like RE 15 for full pressure loads will spike pressure a bit faster than I want. The RE19 will slow that down just enough to are the bullet more gently into the rifling. I also can get the most from a slower powder by having a longer than normal barrel.

[Love Life]

Also, might I suggest an actual drawing board for your tests and notes? It allows you to stand back and see the whole picture at once instead of flipping through pages. I currently have one up on the garage wall while I shoot coated boolits through as many different handguns as possible with both standard and polygonal rifling.

[runfiverun]

could come from the faster powders.
the trick is when does the shove come and when does it let off.
do you want muzzle blast affecting the release, or do you want to allow the boolit to get further down the barrel before being pushed hard.

[Love Life]

Yep. Stuff like 2400. Key is to use the 2400 for appropriate load levels. At 1750 fps the pressure is still low enough to allow decent accuracy. If I tried to go 2100 fps with 2400 the accuracy wouldn't be there, he bullets would be damaged enough on ignition to make it not worthwhile.

Trying to use a powder like RE 15 for full pressure loads will spike pressure a bit faster than I want. The RE19 will slow that down just enough to are the bullet more gently into the rifling. I also can get the most from a slower powder by having a longer than normal barrel.

2400 is actually fast in the grand scheme of things. At least according to the burn rate chart it is.

[btroj]

Also, might I suggest an actual drawing board for your tests and notes? It allows you to stand back and see the whole picture at once instead of flipping through pages. I currently have one up on the garage wall while I shoot coated boolits through as many different handguns as possible with both standard and polygonal rifling.

Handy thought of that. Makes sense though. Lets you see things side by side and you might notice someone you wouldn't have otherwise.

Good idea

[btroj]

could come from the faster powders.
the trick is when does the shove come and when does it let off.
do you want muzzle blast affecting the release, or do you want to allow the boolit to get further down the barrel before being pushed hard.

And how much of that is affected by barrel length? Mine will be around 28 inches so pressure has more barrel to drop off before the bullet leaves the muzzle. Totally different than what a 20 inch barrel might want.

[Love Life]

could come from the faster powders.
the trick is when does the shove come and when does it let off.
do you want muzzle blast affecting the release, or do you want to allow the boolit to get further down the barrel before being pushed hard.

If the crown is cut right, shouldn't release (from the muzzle) be stable across the spectrum?

[btroj]

If the crown is cut right, shouldn't release (from the muzzle) be stable across the spectrum?

Should but reducing muzzle pressure could make a slight difference. If my crown isn't right I know who can fix it.

I think Run is also looking at the relax point where the pressure drops below the level needed to fully obturate the bullet into the bore. He finds that a small lune smear often is found there, right Run? Something else to look at when do pairing burn rates. Barrel length makes a difference here too.

[Love Life]

I definitely agree that barrel length makes a difference. However; in getting the most out of the rifle, dropping to the old standby of 2400 seems kind of...I don't know...meh. Most of the rifle loading members here (who load with cast boolits) make that combo work, so it really wouldn't be a work out at all.

Pushing the envelope is where the learning will come in. They aren't my rifles, so all I can do is put forward my opinion.

So why would a lube smear be found at the relax point? If indeed that does occur, wouldn't a slow powder that pushes the bullet the entire time down the bore (no relax point) eliminate that?

What is the relax point? From what you posted it is the point where pressure drops below the level needed to fully obturate the bullet? Interesting. So would it be better to use something that keeps that pressure up during the entire trip down the barrel?

[btroj]

The 2400 would be no challenge at all. It would be used for times when I decide I don't want the noise and recoil of a 2400 plus fps load. Sometimes it is just fun to go pull a trigger.

The relax point, as Run calls it, is something new to me. My understanding is just what you said, where the pressure no longer fully obturates the bullet. The smear is because the lube is also held under pressure and at this point a small amount can escape the pressure and get left there.

Maybe we can get Run to chime in and more fully explain.

And yes, keeping pressure up the the trip down the bore reduces relax point troubles but increases muzzle pressure that can also be a problem, or so I am told.

In the end it all comes down to finding a balance.

[Love Life]

I don't understand. Leaves lube there? Doesn't the boolit impart lube the entire way down the bore? It's not like the boolit is shrinking at that point...or is it?

I mean once a bullet is obturated it's obturated...right?

[btroj]

Not entirely. If it was a soft, almost pure lead bullet then yes. A harder alloy has some spring. It will obturate under pressure but when pressure relaxes it will spring back to the initial size.

This is why most fire lapping write up suggest a very soft bullet. It squeezes in a tight spot and stays that size so it removes the tight spots. A harder bullets keeps riding the bore up and down the tight and loose spots so it polishes but doesn't remove tight spots.

What happens when we size a hard or soft bullet thru the same size die? They don't come out the same size, do they?

Think of annealing brass. It changes the final neck diameter, doesn't it? Has to do with spring back differences between the harder or softer brass.

[Love Life]

That makes sense. Now once the relax point is reached, and the boolit contracts, it has lost it's fantastic boolit to barrel fit. So, in my mind, keeping the juice on until the boolit leaves the barrel would be the way to go...I think.

[geargnasher]

Speaking of neck tension and neck expanding dies, here's something I started pondering a couple of years ago: Elasticity.

Cartridge brass is flexible, but it is also malleable. Squeeze it a little, it bounces right back. Squeeze it more, it stretches and bounces back much less. Anneal it, it loses a lot of its flexibility.

Sometimes we need hard, springy necks to improve boolit guidance, sometimes we need the brass to just blow up like an old sock and let go of the boolit with minimal influence on it. Sometimes we need a lot of neck tension to improve ignition or for mechanical reasons, sometimes we need as little as needed hold the boolit.

When we finally get worked out the thickness, preferred state of anneal, and tension for a particular gun, what are we going to do to prepare it for the next loading to minimize working? Also, does the requirements of the rifle system allow us to work within the elastic zone of the brass, or must we squish it past it's flexy limit to a smaller size to regain the tension needed? Are our necks of sufficient uniformity to allow effective use of a bushing die, or do we need to size a bit smaller and expand for uniformity? That all depends on the components and system, but generally I like to finish with some sort of expander, even if it's not doing anything except letting me feel how much grip the neck has on each case.

Here's an example: 7mm-08, brass made from '06 or .270 Win. Necks formed from the shoulder of the parent case, very hard, very tight clearance in the chamber. I made tools that would give 1.5 thousandths interference fit with the boolits. After firing, there was still 1.5 thousandths interference fit. The necks were hard, thick, and VERY springy. So, even with loads cooking along at over 2600 fps, the original VLD chamfer I used was all that was needed to seat boolits after every firing. No prep necessary, just deprime, clean the brass, reprime, charge, and poke a boolit into it. Five firings later not much had changed, no neck splits, only one or two cases showing odd springback out of 30.

Most of the time, that situation doesn't happen for me. I need to scrunch the necks a bit to get the tension the gun likes after each firing. So, I have to go about a thousandth or so UNDER what I need with the sizing die to allow for springback (this number varies greatly of course), and guess what? The necks usually don't all spring back the same. That's when I use the expanding mandrel to sort by state of anneal. The softer necks get grouped and fired more and the harder ones rested, or the soft ones worked in a factory FL rifle resizing die a few times until they match the hardest ones in the batch. Then I use the "finish" expanding mandrel to uniform the necks. How much to size down and now much to stretch them out again depends on the non-deforming elastic zone of the brass. Keeping under two thousandths interference fit in a bottleneck rifle cartridge generally makes it so that seating a boolit doesn't permanently stretch the brass when seated, but is still within the brass's elastic zone. This is ideal IMO, you can pull a boolit and the neck pops right back where it was, very consistent way to hold a boolit.

RCBS makes good expanding dies, and one can customize some of the other "M" style dies to do exactly what's needed, even flare a bit as required. Speaking of flare, I like just enough to get about 2/3 of the gas check to sit inside, and about 10-15 degrees of flare angle.

Gear

[btroj]

For belling I agree, get the check started smooth and no more.

So when sorting by neck tension it is all by feel? Sort of gauging the effort required to expand the necks? Interesting.

I also find it interesting that you end up with some cases being fired more times than others. Makes me wonder if some is because of differing hardness in the body of the parent brass that is now your neck?

Just shows that Bass was right, it only matters when it does. Key is finding when it does and what to do about it. Well, that and observing that a difference existed in the first place.

The devil is in the details, isn't it?

[geargnasher]

That makes sense. Now once the relax point is reached, and the boolit contracts, it has lost it's fantastic boolit to barrel fit. So, in my mind, keeping the juice on until the boolit leaves the barrel would be the way to go...I think.

Lube affects this to a very large extent. Using alloys that are springy is important, too. When the boolit goes through the throat it swages a bit, but maybe swage is the wrong word, maybe just gets squeezed like a balloon. When the pressure falls off, the obturation is maintained by the stored compression force of the boolit, like a spring. Also, the barrel is a spring, opening some under the pressure of the boolit and closing behind it, snake swallowing an egg syndrome. If the lube doesn't roll with the punches, it gets smeared behind as the sliding speed increases past its limit to flow. It's all a balance, just like a race car engine where each part must be tuned to work just so with every other part, the available fuel, air, and class rules.

Gear

[btroj]

Balance is sort of the key in all this, isn't it? Too much of a good thing isn't better, often it makes things worse.

[Love Life]

All this being said in this thread I have one question. Is the juice worth the squeeze?

[btroj]

Yes, it sure is.

Is there anything more satisfying than making a system work? Identifying problems, coming up with solutions, and seeing them thru?

Like I tell my daughter, anything worth doing is, by nature, difficult. Easy to do stuff is not very satisfying as anyone can do it. Accomplishing the difficult is what makes us different.

[geargnasher]

I like to feel the spring of the necks when expanding and when seating the boolit. The Forster seating dies mask the seating feel a bit, but it's a good trade-off. Sorting into batches doesn't make for even counts to be fired for groups, but when you can sort into three piles, shoot three small groups, and overlay the targets to find the aggregate size is double, or was half of what you were doing before when not paying attention to neck tension, lightbulbs start to come on.

I've use beam-type torque wrenches before, but once I got tuned in on the feel of the press handle, that has become my method. Every once in a while you'll find a dud case, one that just won't give good tension. Often, it will have a soft spot in one place that will show up when you check concentricity after seating a boolit. One time I took three duds from a batch and marked them. I shot some good groups, then fired one of those marked ones into the group......FLYER. I says Ahh---HA! It DOES matter! That's when I started paying very close attention to neck tension uniformity.

Gear

[Love Life]

With balance being the key, will the results be transferable? Is this NASA level knowledge only realized and benefitted from in custom rifles or can billy joe bob take the lessons learned here, fill his favorite cartridge with 'splody powder, seat is best cast boolit, and go get real jacketed performance.

When I smoke out the barrel on my rifle...again, I'll throw the 308 barrel back on. It is chrome lined and stuff and mebbe I can join the fray, albeit with a 308.

What is good for the goose (lessons learned here) should transfer to being good for the gander.

Now, neck tension, perfect brass, etc has been discussed. How are you going to get near perfect boolits? I wonder if cast and lubed boolits run into a swage die (so lube is retained, but voids and stuff eliminated) would be the ticket on that front.

[geargnasher]

All this being said in this thread I have one question. Is the juice worth the squeeze?

I dunno, was the Fat Lady experiment worth it? I'll bet it was to you.

Gear

[Love Life]

Yes it was.

However; what theories are being proven or disproven here? RPM threshold? Brass prep? Boolit quality? Necessary pressure? Lube?

Who has the equipment to measure all the variables? Do you have an Arbor press Gear? I have a pressure gauge that measures seating pressure and you're welcome to it as it may aid in your research concerning neck tension.

[geargnasher]

To really attack the broad subject Brad started with here, we might best be served by breaking it down into some transferable, minute details under several sub-sections. For example, the subject of neck tension, flare, and chamber neck clearance is but one tiny part of cartridge case preparation for accuracy. In general, close tolerances are the key, when and where we can get them, but what if Bubba with his wallered-out '06 chamber can't get components to do that? There are tricks to help, but maybe he'll never get to shoot accurately at high velocity with that system. So there are general guidelines, and there are different specific approaches to tackle the individual rifle personality and work within what's given. Remember, I'm still just referring to neck tension, flare, and chamber neck clearance here.

Ignition consistency and how that relates to barrel harmonics is another lengthy, variable subject. Generally, with a bolt-action, having consistent pressure between the datum point on the shoulder and the bolt face makes a very noticeable difference in point of impact. I say that in a general sense because I've found it to be true in three rifles, one of which uses a rimmed case. When I started headspacing on the shoulder and sorting rounds fired based on lever effort to latch the locking bolt, my group shape improved dramatically. Does that subject fit under case prep? You bet it does, because you're controlling action preload, and thus the transfer of energy between cartridge case and action/barrel, at the reloading press.

I think it's possible to break this down into basic categories, share experiences that affect the same subjects differently in different situations, and get a sort of general set of "what works and what don't" guide that others may be able to absorb, but in the end each handloader is going to have to hash it out for themselves. Having a set of guidelines and discussion of what affects each part of the fitting, loading, and shooting process in various guns/calibers may help shorten the learning curve a bit, but I think it would be a full volume or two. Take the four points I made way back on page one and expand them each into several hundred pages, then you might have it covered. Then someone who knows a lot more about this than me will add a few other topics and it gets huge again discussing them in detail.

Take the statement "get the boolit into the bore absolutely straight", which is what Bob has told us over and over again, then take two years of your life figuring out how to accomplish that in just one gun. That's what I did, and I know I only learned part of what to do.

Gear

[Love Life]

Sounds solid to me.

I know sharing info can be frustrating (especially on a gun forum) because everybody wants to chime in (I'm doing it now!!) with "stuff". Then it evolves into a monster. However; nothing is stopping the OP or group of contributors from bulling through the noise and then summarizing at the end and allowing onlookers to make their own decisions on what they want to do. In guided discussions, you guide it. Ignore the fluff (like this post...) and keep it on track.

I've seen it mentioned several times in the last week how terrible it is that some members won't contribute because they want to be in control. Well...then they have made themselves useless and irrelevant for the most part.

I want to thank all of you for going down this road and for the hours of research and trial and error you are about to do.

Thank you.

[btroj]

So much of it is learning what to look for and how to look for it.

When I started shooting Highpower I figured case lube was case lube. Read a few books, do some testing, do some measuring. What did I learn? That how we apply lube makes a difference in that bolt face to datum line measurement Gear mentioned. Yep, over lubing the neck and shoulder can lead to a .001 change in that measurement quite easily.

Ok guys, Gear made a good suggestion. Break this into little bits and take it in manageable bites.

What bite first? I will let someone else start that thread.

[Love Life]

First bite? I'd say brass prep (getting your brass perfect-ish for your gun) or boolit quality needs to be first. Those will be the largest variables to confront you 1st. I have tools to lend (concentricity gauges and stuff) to help, but sadly I am unable to contribute where the tires hit the road.

So, that being said I will bow out of this and watch from afar. Pm me if any of you want to borrow some stuff.

[geargnasher]

I'm not really interested in proving or disproving anything, only finding what works. All moving objects have resonant frequencies and multiple harmonics of those frequencies (study music theory or listen to Eddie Van Halen play guitar and you'll learn a bunch), and boolits and rifles are no different. Orbital mechanics is enough to show us that there will be several ideal, 'smooth' rotational velocities for a given object. A given rifle system has ideal and non-ideal performance points, it is a fact, not a theory. I'm interested in working with these facts and postulating solutions to "limits" as they are encountered, testing those theories, and finding factual solutions to things we think are issues, like pushing past an accurate velocity limit in a particular rifle. Some things we know, some things we don't but have our pet theories. What I like to do is use theoretical discussion and educated guesses to devise tests that will give us facts, and bury the theories that when tested, don't lead us in the direction we want to go.

As for equipment, people on this site have devised and improvised all manner of neat stuff to test things. We need to quantify variables so we can study them effectively and compare the effects of measured changes to those variables. THAT is what I want to do.

I made a Timken-style wear tester to compare film strength of various lubes from zero to several hundred degrees. It has been handy, but only tests one thing that may or may not be relative to the system. A micrometer, reloading scale, and a lot of "feel" is required, too. The best tool for testing so far has been my mind, and the target has been the best way to solidly judge results.

Gear

[geargnasher]

OK, Brad, let's deviate for a minute and poll how to break it down, because I don't know it all by a long shot.

We could do it like this: Come up with the main topics (evaluating the suitability of a rifle for the task [crown, bore condition, straight chamber, pound casts, reading light rings, checking headspace, bedding, etc etc], guidelines for how to fit ammo and boolit, case prep techniques for various chambers, how to make a good boolit [casting, sizing, checking, quality-control, etc], mechanical loading techniques aimed at fit, harmonics, and not damaging the boolit during launch, loading techniques to solve problems, on and on.), and THEN let the OP keep updating and modifying THE FIRST POST to distill the facts for readers. The discussion, demonstrations, etc. could go on for hundreds of posts, but the key points and facts keep getting pulled to the front just like Tim's "Accurate Molds" thread where contributions are compiled into the first post in an orderly manner.

Whatcha think? The topic of this thread is broad, "Making the most of a good rifle", so what does that mean? How do we want to break this down into, say, less than ten separate subject threads?

If we got it narrowed down to just a few main topics, and perhaps left the gunsmithing/rifle building part to a separate thread and focused on JUST how to "run what ya brung", we could get the staff to agree to sticky a few discussion topics ahead of time.....but we need a good plan first.


Gear

[btroj]

Yep, the mind is what matters. That and a desire to learn, and ability to make good observations, and to make appropriate conclusions from those observations.

The how isn't always as important as the what.

Oh, music theory? No thanks, I get enough art history at home. Now Eddie I can do, saw him n concert and he is the real deal.

How much of the harmonics battle is eliminating them and how much is learning to control them or make them predictable? Do we need to worry about resonance of a variety of frequencies? How do we know that time issue and not someone else?

[Love Life]

How would you know if the bullet is damaged (or not) during the jump (unless you jam) into the rifling? How do you know if the rifling is damaging the boolit? I don't feel recovered boolits fired from the gun would show this.

However; what I have in mind is this. I have seen a grease gun with zerk fitting to remove a stuck bullet from the bore. What if something like this could be fabricated, attached to the CHAMBER end, and a grease gun used to push the bullet down the full length of the barrel and out of the muzzle? Wouldn't that give you a good bit of info?

[geargnasher]

Remember the "Basement Articles" Brad? That was my concept, based on only what I know and how my mind breaks that knowledge down, of how to make "small bites". Those were technical, rather than academic articles, and to be effective they really need to be a little bit of BOTH.

Like LL suggested, case prep is a biggie. I wrote "Case prep for accuracy", but it was so inter-related to rifle vibrations, chamber/bore dimensions, and advanced loading techniques that it couldn't be the first topic.

I suggest starting with a how-to discussion of the goals. Accuracy alone? Accuracy at well above (or below!) what's considered average for cast boolits? Accuracy to a hundred yards and to heck with the rest? Accuracy at long distance? Then continue into how to size up your rifle, with reference to threads about how to select parts to scratch-build a gun. I'd let Tim handle that thread, and he can learn a lot from sorting out what's been posted already in the past week or so on that.

I'm going to assume that, if we consider high-velocity cast boolit accuracy as the PRINCIPLE objective, we can drop a lot of the fluff and start right into pound casting, reading light rings, checking the muzzle condition, headspace, and flow right into the big subject of loaded cartridge and boolit fit. I see I have a pm, so I'm going to stop derailing this thread for a minute and see if we can work this out without cluttering up things here...

Gear

[Love Life]

I got to thinking today while I was wrist deep in a bucket of KFC. Why are we discussing obturation. I thought the whole purpose of boolit fit got rid of that. It has me wondering...if the boolit is already sized to whatever you prefer over bore diameter, does it need to obturate? Is it even obturating?

Wow, all the red squiggly lines are telling me I am creating new words.

[btroj]

Because as it travels down the bore it is constantly pulling away from the lands on the trailing edge. Pressure on the bullet and lube prevent gas cutting there. Lose that "seal" and you have leading.
Think of your handgun bullets and the cut coating. What slews the back edge of those cuts? Not the coating.

[Love Life]

I really wish I could nail down a rifle length polygonal rifled barrel. Looks like a call into PacNor is in order. We are concerned about the boolit being perfect from leaving the case to exiting the bore, so is that uber sharp rifling beneficial to a cast boolit?

[runfiverun]

why do even land and groove rifles with fairly deep rifling shoot cast better?

you guy's are on the track of questioning and figuring out why the relax point down the barrel matters and what it relates to too.



here's how I have been getting success.
step one.
focus on the cases [even neck tension/correct case thickness] and the centerline of the barrel relationship first.
get that right.... it don't matter what kind of projectile you are using it matters.
step two.
focus on mechanical fit of the boolit/bullet [think about dicks success with the heavy bullets compared to the lighter ones and why]
step three.
focus on powder speed. [again back to the fat lady why retumbo over 4831]

get all that working together,[and you have success at a reasonable velocity of 23-2400 fps]
this is when start mucking about looking for the other couple of hundred fps.
alloy and lube tweaking are your next two steps, they allow you to add more powder to the case.
at some point you run out of room and have to step up the powder speed, quite often this is accompanied by an oal change.
this is also a point that gets you about 150 feet per second down the road from the initial accuracy node[s].
dial all that in and change primers looking for the final accuracy tweak.
if you make it to 2600 fps, you start changing the b.c of your boolit and down range trajectory [300 yd mark] into something magical.
your also done and bored with the rifle and are looking for a new project...
but every time you look at it you feel a sense of pride and accomplishment.

[Love Life]

R5R and CBRick- Thank you for the information. It gives me a lot to chew on. I don't know why, my mind keeps wandering back to polygonal rifling.

Using coatings, and recovering boolits, it is easy to see the actual cutting that sharp rifling does to the boolit. Also, the recovered boolits fired in polygonal rifled barrels show there is no cutting. Also the leade into the glock barrels is very gentle. I have seen a tangible accuracy difference in my pistolas and borrowed pistolas between the two types of rifling.

Now, according to what I have found, Polygonal rifling creates a better seal and doesn't have te sharp edges: http://www.ballisticsbytheinch.com/rifling.html. I looked other places and much remained the same.

Brad brought up Obermeyer barrels. That also got me to thinking because his (Obermeyer) barrels have a smaller bore diameter for caliber. That is pretty interesting.

Once again though it all comes back to: What are those sharp edges in the rifling doing to the boolit?

My brain hurts and I am off topic which is making the most of a good rifle.


Loading practices will win the day on that one, but I also am getting hung up on boolit design. I see many boolits with a sharp, square shouldered front driving band. Is that beneficial? Would a slow taper down to the bearing surface be better?

[Love Life]

Looks like Lothar Walther makes polygonal rifled 308 barrel blanks. When I burn out the fat lady again that is what I'll get. I will figure this out!!

[cbrick]

Speaking of neck tension and neck expanding dies, here's something I started pondering a couple of years ago: Elasticity.

Cartridge brass is flexible, but it is also malleable. Squeeze it a little, it bounces right back. Squeeze it more, it stretches and bounces back much less. Anneal it, it loses a lot of its flexibility. Gear

That's not entirely accurate and why I call annealing an art form. A very unscientific test of cartridge annealing is to use needle nose vice grips adjusted to just contact the neck, now adjust them in just a bit, .020" - .030" and squeeze the neck and PROPERLY ANNEALED necks will return to it's original shape. Too much annealing and they won't, it may still be malleable but it won't be flexible and it's not because they were annealed it's because they were annealed too much. If they loose this flexibility they give inconsistent grip on the boolit.

Rick

[Love Life]

If the shot matters it does yes.

As long as plinking ammo goes bang not a lot of anything matters short of leading up a barrel. If the intent of a loaded round is to place it in a specific spot on a target over on yonder hillside there is much in the details.

Rick

Troof.

[nekshot]

I think I need a shot of whiskey, but I'm listening!!!

[Love Life]

Must be my limited vocabulary. What is "Troof".

Rick

Troof is a southern drunken slang term for truth. Kind of like far=fire.

Back on topic.

Feast your eyes on this thread: http://castboolits.gunloads.com/showthread.php?238796-rifling-angle&p=2745412#post2745412

Now member Nobade posted this: Quote Originally Posted by Nobade View Post

One thing that has been touched on here is the difference between a modern chamber big enough to chamber a groove diameter boolit and an original Sharps chamber only big enough to chamber a bore diameter boolit. Those nice gentle leades work great when the chamber is very tight, since the boolits don't have anywhere to go. If you start with a modern chamber and add the gentle leade you'll get what Kenny W. says - the boolit will upset into that space and then have to get swaged back down to get into the bore. Remember, those boolits upset pretty much instantaneously. Like inside the case. If the case allows that boolit patched to .450" upset to .462 or so, then it goes through some real torture during its trip.

Those old tight type chambers really work, as does the Dan Theodore design like I have in one of my rifles. But trying to turn a modern chamber into one of those may not turn out as well as you would like.

-Nobade


Then when you look at the drawing posted by Montana Charlie, it makes a whole lot of sense. You seat your .309, .310, .311 or whatever size you prefer in the case. That miniscule space between the case mouth and leade/bump is pretty large in diameter when compared to your boolit diameter. In that miniscule space, is your boolit bumping to fill that space and the swaging down as the booty of the boolit hits the rifling?

Would a case with an OAL that eliminates that gap be mo' better? Would a tighter neck be mo' better in allowing the boolit to keep from bumping up ad staying straight into the rifling?

[btroj]

A tighter neck and a case neck long enough to fill the entire cut for the neck will help. If the bullet has a place to go then it will.
This is also why a slower powder helps. Gives a gentler push into the rifling and reduce the tendency to rivet.

Think BP cartridges of old. How top did they get away at times with what we would call undersized bullets? The BP pressure had an initial pressure spike that obturates the bullet to fit the bore. Smokeless doesn't always do that well in those cases with the same bullets because of a progressive burn rate. Slow the pressure spike and those bullets lead like crazy.

Sometimes old is new.

[runfiverun]

popes stuff was based on using a bore diameter boolit.

BUUUT with a small bumped base of groove diameter, the boolits were breech seated.

this is also a common practice now days with jacketed bullets where for say a 223 bullet everything is normal except for a ring on the base that is 2245.
I have a die set made this way with a 6s ogive, it looks wrong but the holes in the paper are sure hard to argue with.
it does give me fits loading them at times though as the ring want's to open the case neck.
I have to slightly re-shape the case mouth/necks on soft brass to match the bullets taper after it's loaded.
I wouldn't bother but those 1/2" groups and easy 300 yd shots on rock chucks from my
stag 6-H are hard to argue with.

Dick think about how does the boolit become aligned after it isn't quite moving along but the case neck is opened.

those square shoulders.
how are they going to help when the throat isn't square but tapered and maybe not concentrically, and the drive bands are not in there yet.
how about in the ball seat area [leade] that square front band?
what happens to it when it moves forward into the tapered area.
where does that displaced lead go? does it go there evenly every time?

[Love Life]

popes stuff was based on using a bore diameter boolit.

BUUUT with a small bumped base of groove diameter, the boolits were breech seated.

this is also a common practice now days with jacketed bullets where for say a 223 bullet everything is normal except for a ring on the base that is 2245.
I have a die set made this way with a 6s ogive, it looks wrong but the holes in the paper are sure hard to argue with.
it does give me fits loading them at times though as the ring want's to open the case neck.
I have to slightly re-shape the case mouth/necks on soft brass to match the bullets taper after it's loaded.
I wouldn't bother but those 1/2" groups and easy 300 yd shots on rock chucks from my
stag 6-H are hard to argue with.

Dick think about how does the boolit become aligned after it isn't quite moving along but the case neck is opened.

those square shoulders.
how are they going to help when the throat isn't square but tapered and maybe not concentrically, and the drive bands are not in there yet.
how about in the ball seat area [leade] that square front band?
what happens to it when it moves forward into the tapered area.
where does that displaced lead go? does it go there evenly every time?

All very interesting!!

How does the boolit stay aligned when the case neck is opened, but the boolit hasn't launched yet? I don't know to be honest. If it's jammed then I could say the ogive is holding it in place. Is that what is achieved with the bore riders?

Those square shoulders...are they a help at all? Are they a hindrance? Is their existence even important? Would a lack of square should, but instead an angled back shoulder, better?

Where does the displaced lead go and does it go there evenly every time....? Aha!!! With voids, no. I would assume the swaging down/crushing of the boolit as it enters the bore, the metal will deform into path of least resistance in the boolit. Which would be a void. We can't choose where the voids are.

[geargnasher]

LL, understand that OBTURATION means TO SEAL or PLUG, it does not describe the action of pressure deforming a boolit, but rather the result of a gas-tight boolit/bore interface due to whatever reason, be it powder gas pressure swelling the base or just a good fit with good, springy alloy.

The short version is just like Bob mentioned the other day: Make a pound cast of the chamber and throat and duplicate that with your loaded ammo. Use good boolits. I'll continue in my own words: Use the right alloy and powder to achieve a manual breech-seating condition upon initial ignition and then "baby" the boolit through the rifle, or however you have to program the launch for your particular platform so as to not damage the boolit. Tune the powder and fit of things until the harmonics are cooperating. Done.

Gear

[btroj]

I dislike those square shoulders. I prefer a taper from nose to full diameter.

What keeps the bullet aligned after the neck expands but before the bullet moves? That is why a snug neck makes a different. If the loaded round is only .001 smaller than the neck is cut then it can't move to the side or rivet much, can it?

Even wothout a void in the bullet the more we contain the bullet and give it little room to expand into the better off we are. Lead under pressure is a pretty plastic material and it will expand into abput any space we let it expand into. Keep the neck dimensions snug, the case neck as long as possible to fill the entire neck cut in the chamber, and let the bullet fill the leade.

[geargnasher]

Any time you exceed the alloy's ultimate compressive strength, it becomes plastic. We have two choices here, either don't exceed that pressure until the boolit is fully contained within the barrel, or contain the boolit from ignition on.

Gear

[Love Life]

Word up and I'm out of here. I need to take some measurements.

[btroj]

Any time you exceed the alloy's ultimate compressive strength, it becomes plastic. We have two choices here, either don't exceed that pressure until the boolit is fully contained within the barrel, or contain the boolit from ignition on.

Gear

Yes sir. Slow powders sure help in that regard.

[Love Life]

How slow? Is it bad that I now look at 4831 as a fast powder? :grin:

[btroj]

Slow is relative. 4350 is slow in a 30-30.

Think slow for the cartridge. I think of a powder normally suitable for the next size case up for the same bullet diameter.

Use an 06 powder in a 308 for example.

[Love Life]

I appreciate everybody taking the time to answer my rather noob questions in a manner that I could understand. I'm off to hunt Easter eggs!!

[geargnasher]

Yes sir. Slow powders sure help in that regard.

There are other things that help as well with "reversing" the typical pressure curve shape as much as possible, particularly in short barrels at high velocity.

Gear

[btroj]

There are other things that help as well with "reversing" the typical pressure curve shape as much as possible, particularly in short barrels at high velocity.

Gear

Ok, how do we do that?

[geargnasher]

Depends on the application. Take my 20" Marlin 336, in .30-30, for example. Short barrel, fast twist, not a good combo for HV. Terrible throat, too, meaning the potential for initial launch damage is very high. I finally figured out how to use a RD design boolit seated to pilot nicely in the sharp throat, and used just the right alloy (60/40 WW/pure) so the boolit could span that "auditorium" between case mouth and sharp-angled throat without scrunching up like an inchworm. Well, almost. The last trick was to use a fast-burning rifle powder (Reloder 7) to give me two things: Low muzzle pressure, and enough room for enough compacting shot buffer to squeeze that boolit into the bore without wadding it up like the wrapper on a soda straw. I use enough powder and enough buffer to get me 2100 fps, actually the powder alone gets about 1800 fps, the buffer raises pressure that much), and the thing is quieter than a .22 Magnum. There is almost no muzzle pressure, just a loud "POOF", almost a sub-sonic concussion sound, or maybe the supersonic crack is louder than the muzzle blast, IDK. I shot the load several times without hearing protection when hunting and it's not loud at all, and I have sensitive ears.

Getting the right powder, right alloy, right powder/buffer combination, and right boolit for all that to happen took some time, but I had a THEORY that gentle push at launch, quick burn like a top-fuel dragster, then shut it down and hit the parachutes right at the finish line would make the most out of this short-barreled rifle. I was right.

I'm pretty much ignoring muzzle pressure in my .308 with a 20" barrel, and the "improved" case boosts pressure as the boolit engraves considerably over the slope-shouldered .30-30. The H414 (what has worked best so far) gives a mighty muzzle blast. Those two things are working against me, even with a textbook benchrest neck and boolit fit. I'm not sure the best approach here, but 1.25 MOA at a hunnert for ten, consistently, at near 2400fps is right about where I want to be anyway. Haven't tried backing down the powder a few grains and experimenting with buffer, YET, but that will likely be next for the Savage Pig Gun.

Gear

[geargnasher]

Now I'm going to throw a monkey-wrench into the gears.....Some of the F-class guys, using the 6mm BR and Norma brass, have discovered that giving MORE neck clearance (up to .002" total vs the normal .0008"!) improved groups significantly, particularly at 200 yards. Now why would THAT be, and does it sometimes work that way with cast boolits?

There are three more areas to look into for our fit than just neck clearance, too. Datum length, case body fit, and the oal of the brass you fellers were just discussing. BTW, I get lube rings or paper rings with shorter-than-chamber brass, but not lead rings. Why is that?

Gear

[geargnasher]

[snip]
The point I'm trying to make is that these techniques work in a bolt action pistol, they work in long range revolver and they would work just as well in a rifle. A tight chamber allowing very little brass movement with the boolit perfectly aligned with the center line of the bore. Boolit sized so there is no swaging down, no bumping up, no molesting the boolit at all. Then of course is the slowest powder that will get you to your desired velocity giving your boolit a nice gentle start as opposed to smashing it in the heiny with a sledge hammer.

Rick

And a good point it is. Figuring out ways to accomplish what you say there is most of how I've gotten the results that I have. I can shoot itty, bitty groups at 'normal' velocities doing just that, and pretty decent groups way on up there in velocity. Some people do much better than I do with it at HV. But really, what you mention is the limit of what the CBA guys seem to know, there's more to it than that, and trying to learn the rest is why I'm still here. This is where Bob could really contribute.

Gear

[btroj]

Yes, Mo better for sure. I had a 6BR built by Ralph Bond in Indiana, this was the very most accurate firearm I've ever owned, it incorporated much of what is discussed in your post. Brass length fit perfectly and tight chambered where neck sizing reduced the neck by about .0005". Scary accurate. The downside is that this was before I went exclusively to boolits but there sure is something about a 15" handgun at 3000 fps that would shoot the hair off a gnats hieny at 200 meters.

I use this technique in revolver loading also, in 357 I use 360 DW, 41 Mag uses 414 Super Mag brass etc. trimmed to fit the FA chamber perfectly right to the throat. A heavy for caliber boolit sized to a mild snug fit in the throats & with the lengthened brass the entire front driving band is seated fully in the throat. With .357 boolit and throats and a .357 groove diameter, the boolit well aligned with the center line of the bore it's through the throats with zero re-sizing, a perfect size match into the bore with zero re-sizing & no riveting at the forcing cone.

The point I'm trying to make is that these techniques work in a bolt action pistol, they work in long range revolver and they would work just as well in a rifle. A tight chamber allowing very little brass movement with the boolit perfectly aligned with the center line of the bore. Boolit sized so there is no swaging down, no bumping up, no molesting the boolit at all. Then of course is the slowest powder that will get you to your desired velocity giving your boolit a nice gentle start as opposed to smashing it in the heiny with a sledge hammer.

Rick

That pretty well sums it up. The devil is in the details.

Why have a gun with such closely refined dimensions then feed it garbage?

[btroj]

I can't speak for others but I prefer to learn. If that means dealing with a grumpy old man at times then I will, at least as long as it benefits me.

[Love Life]

In customed chambered 30 caliber full bench rest cast bullet rifles they are typically cut two ways.On is the Ardito style that starts at the end of the chamber very large at ..312 or better with a 1 degree or shallower taper to rifling.Th other style starts with as section of freebore to just slightly over you specified bullet diameter and out .100 or so then has a 1.5 deg taper(or close) to rifling.Both of these are typically used with bump/taper dies that have the same dimensions as those and bullet fits like a Morse taper.Short of breech seating Schuetzen rifles this is the bast fir and most successful accuracy achieved in 30 caliber rifles in open competition.

The above is written by Member HARRYMPOPE. There is a piece to the fit puzzle.

[Love Life]

If there is any learnin goin on it isn't in these posts now is it? So where is all this learnin?

Rick

Learning town? Hehehe.

[geargnasher]

The real learnin' is awaiting a proper classroom. If you want, there are some good textbooks to read in the meantime, particularly Veral's little pamphlet and F.W. Mann's tome.

Gear

[cbrick]

The real learnin' is awaiting a proper classroom. If you want, there are some good textbooks to read in the meantime, particularly Veral's little pamphlet and F.W. Mann's tome. Gear

Got'em both and more thanks.

As I posted in the other thread . . .


I'll believe it when I see it but I'll not be holding my breath.

I graduated Romper Room 60 years ago, no need to re-attend here. I'm done. Rick

[45 2.1]

The real learnin' is awaiting a proper classroom. Gear

Most people who went to school learned not to disrupt the class....... or you got a trip to the principals office and detention. In case most of the participants of this thread missed it, the knowledge you seek is in the archives and general posts on this and the previous iterations of this site. If they missed it, it is their fault for not paying attention, or believing the wrong people. Just looking at the posts here I see a bunch of people, like the disruptive students in class, who want without doing their homework. If you want to do better, then a proper classroom with a proper teacher, is warranted as Gear said.

[45 2.1]

The above is written by Member HARRYMPOPE. There is a piece to the fit puzzle.

John Ardito cut the throats in the rifles he made that way. He also had the mold made that way also.... to fit that throat. A question: Does the barrels throat fit your boolit or does the boolit fit your barrels throat OR does it do neither? That determines whether or not the second method works or not.

[Love Life]

I got the thinking again (dangerous) about the relax point, obturation, and spring back...and compression.

It was said that springback due to alloy was an issue as the juice started to let off as the boolit traveled the bore. Hmmm. Shouldn't springback keep the bore sealed since the boolit is compressed into the rifling, and it's springiness should keep it pushed into the rifling?

If the boolit does indeed compress (or shrink) away from the rifling...why does it do that?

I mean you are shooting .00whatever over bore diameter right? Spring back shouldn't even be there.

[geargnasher]

Good question. Compression at engraving and alloy springiness should maintain obturation regardless, at least in a perfect world. Rifle bores, even good ones, aren't perfect worlds. I can't prove it, but I'll throw out there that I think a lot of the "relax point" is the effect of lube being purged out of the grooves and trailed behind the boolit as pressure drops off. There is plenty enough gas leakage past the gas check and base to pressurize some or all of the lube grooves at peak pressure. As the pressure drops off toward the muzzle, it stands to reason that the lube might get squirted back out behind the boolit the same way pressure got in there, through tiny trailing edge leaks. Changes made only to lube viscosity by adjusting the proportion of an otherwise fairly inert ingredient will affect the time and place of a lube smear, or eliminate it entirely.

Gear

[Love Life]

Gear- Which of the boolits pictured would meet the criteria for leaving the barrel with minimal damge?

[btroj]

LL, think beyond rifling marks as damage. Think of bullet slump, uneven rifling marks from off center entrance into lands, or gas erosion in spots. Skidding along front bands can be damage too.

Lots of potential pitfalls in a rifle barrel for a soft lead bullet. Think of what happens in a revolver! It amazes me they can even shoot.

[Love Life]

LL, think beyond rifling marks as damage. Think of bullet slump, uneven rifling marks from off center entrance into lands, or gas erosion in spots. Skidding along front bands can be damage too.

Lots of potential pitfalls in a rifle barrel for a soft lead bullet. Think of what happens in a revolver! It amazes me they can even shoot.

Understood. However; which boolit looks like it had a gentler ride through the barrel?