cast bullets and high velocity cartridges

[xdmalder]

Is there a point to using cast with cartridges such as 308 win since it is capable of so much more velocity than what can be utilized with cast hunting velocities. I know people have gotten velocities with bullets that match jacketed velocities but in hunting wouldn't they just fragment heavily on impact

[Texas by God]

Range is the only tradeoff for using cast for hunting. The cast bullet holds together and penetrates rather than expands. Flat noses provide the trauma needed for killing. Velocities can be achieved close to 2500 fps but I imagine leading becomes a problem. Best, Thomas.

[Hickory]

There are no set rules or limits on a particular rifle until you find them.
What I mean is that you have to find the right alloy for the velocity that you want to achieve in your gun and still perform well as a hunting boolit.
A good velocity to start with is 1800fps with a boolit BHN around 12-15 for hunting. (I'm assuming you are hunting thin skinned animals like deer or elk.) Lead and tin with a small amount of antimony will give the best expansion and hardness. Too much antimony may cause the boolit to fragmentate on impact.
Once you find a good accurate load at 1800fps you can work up from there. As long as there is no boolit leading and the accuracy is good you keep going up in velocity until accuracy deteorates or your gun starts to lead the bore.

There is a good chance that you may not get much velocity past 2000fps in the average gun, but, all guns are different and one gun should not be a standard for or against another.

Part of the reason the 30-30 is such a good cartridge is that it can reach its velocity potential with either cast boolits or jacketed bullets.

This is the fun part of reloading, and using cast boolits for hunting or target work is finding the sweet spot that make your gun shine.

[popper]

The advantage of 2400 fps is drop. Consider terminal fps for what you shoot. If cast doesn't 'explode' 1800 @ 100 yds, 1800 @ 200 yds won't either. I shoot 308 @ 2700 without leading.

[waksupi]

I have used the .308 at 2450 fps, and it worked fine on deer. Velocity was actually higher than I like for cast, but it was what I had at the time.

[xdmalder]

I have used the .308 at 2450 fps, and it worked fine on deer. Velocity was actually higher than I like for cast, but it was what I had at the time.
Which mold were you using

[xdmalder]

Is there a possibility of using a spitzer style bullet for hunting and shooting at a velocity of 2400 fps to get the range and the bullet to perform terminally and down range

[quilbilly]

Is there a possibility of using a spitzer style bullet for hunting and shooting at a velocity of 2400 fps to get the range and the bullet to perform terminally and down range I have spitzer molds in both 25 and 30 calibers and after doing terminal ballistics tests in soaked phone book media, I wouldn't use them for hunting. I got better hunting performance with either round nose or round nose with a small meplat. The spitzers were unpredictable often either breaking up or veering off out of the media prematurely. Round nose with a small meplat gave best penetration and good expansion depending on the hardness of my alloy. Bruce B had a method for doing a soft nose for bullets that would improve hunting characteristics for a spitzer but I have never tried it.

[Wolfer]

This is just my opinion so take it for what it's worth. That some people shoot hunting suitable alloy well above 2000 fps with good results I have no doubt. What I think you'll find is these people have considerable experience. Getting good cast results below 2000 fps is fairly easy, above that things can get more complicated.

All of my cast boolit rifles could be called a 30-30 or 35 rem. Regardless of cartridge they all push a 170-200 gr boolit to 1700-1900 fps. These work very well at woods ranges.

All rifles are different but my 700 Rem in 30-06 when lined up 2" high at 200 yds with 168 triple shocks for elk hunting shoots about 1" low at 100 yds with the 311041 at 1800 fps. IMO this is a very usable combo.

Some of my guns require some sight adjustment between cast and jacketed. These are generally dedicated cast or jacketed rifles.

[tdoyka]

There are no set rules or limits on a particular rifle until you find them.
What I mean is that you have to find the right alloy for the velocity that you want to achieve in your gun and still perform well as a hunting boolit.
A good velocity to start with is 1800fps with a boolit BHN around 12-15 for hunting. (I'm assuming you are hunting thin skinned animals like deer or elk.) Lead and tin with a small amount of antimony will give the best expansion and hardness. Too much antimony may cause the boolit to fragmentate on impact.
Once you find a good accurate load at 1800fps you can work up from there. As long as there is no boolit leading and the accuracy is good you keep going up in velocity until accuracy deteorates or your gun starts to lead the bore.

There is a good chance that you may not get much velocity past 2000fps in the average gun, but, all guns are different and one gun should not be a standard for or against another.

Part of the reason the 30-30 is such a good cartridge is that it can reach its velocity potential with either cast boolits or jacketed bullets.

This is the fun part of reloading, and using cast boolits for hunting or target work is finding the sweet spot that make your gun shine.

i agree with that.

i use a 30-40 krag that does about 1800fps using a 165gr ranch dog. i have used three different powders(h4198, rel 7, and varget) and i never went above 1900fps. i could have, but i didn't even try to. i only go above 2000fps in my 444 marlin. this year i want to see if i can take a 280gr wfn gc down to 1800fps.

1800fps seems to be a real good spot for a rifle cartridge. except for my 45-70, it only goes a whopping 1300fps with a 405gr fbfn!!!:mrgreen:

[dverna]

I settled on the 165 gr Sierra GameKing for my .308. It is an extremely accurate bullet and will perform well at any range under 400 yards. The 500 I have will last a lifetime

Cast bullets do not offer any advantages in the .308 so I see no point to using them. And at about $.30 each for the GameKings, not worth the effort. And they are less expensive to shoot than cast......WHAT YOU SAY!?

Yes CHEAPER.....

There is a lot of load development that normally goes into finding an accurate cast load at 2500 fps. Different alloys, different bullets, different sized diameters, different lubes, different powders....That all costs money.

With a good jacketed bullet you will have an acceptable load after testing 100 rounds. In both my .308 and .300 Win Mag, I had a very good load after shooting 50 bullets. Try that with a cast bullet.

For me, cast rifle bullets used for hunting have their place in slower and heavier applications. Where a long shot is 200 yards. Limit the range with your .308 if that suits you, but you will regret it the first time you have a 350 yard shot down a power line or across a corn field.

Don Verna

[Texas by God]

Cast bullets will increase the .308's versatility. If Nebraska allows rifles for hunting Turkey you can use cast and not blow a fist sized hole through the bird like a high velocity jacketed bullet will. I've used cast in my 25-06 but I would limit range to 100 yards. I will continue to enjoy using jackets for high velocity cartridges and cast & jacketed for rounds that operate between 2000-2500 fps. Best, Thomas.

[tdoyka]

I settled on the 165 gr Sierra GameKing for my .308. It is an extremely accurate bullet and will perform well at any range under 400 yards. The 500 I have will last a lifetime

Cast bullets do not offer any advantages in the .308 so I see no point to using them. And at about $.30 each for the GameKings, not worth the effort. And they are less expensive to shoot than cast......WHAT YOU SAY!?

Yes CHEAPER.....

There is a lot of load development that normally goes into finding an accurate cast load at 2500 fps. Different alloys, different bullets, different sized diameters, different lubes, different powders....That all costs money.

With a good jacketed bullet you will have an acceptable load after testing 100 rounds. In both my .308 and .300 Win Mag, I had a very good load after shooting 50 bullets. Try that with a cast bullet.

For me, cast rifle bullets used for hunting have their place in slower and heavier applications. Where a long shot is 200 yards. Limit the range with your .308 if that suits you, but you will regret it the first time you have a 350 yard shot down a power line or across a corn field.

Don Verna

i limit my range whenever i go to hunt deer. its is 150 yards using cast boolits and it will go 300 yards using a jacketed bullet. i have had the chance to shoot a six point whitetail while using my 444 and a 275gr ranch dog. i didn't shoot it because it was 187 yards away(laser range finder). i told my dad to go ahead and shoot it and he did, it was drt. it was shot thru a field. could i have shot it? yes i could have. but i CHOSE the 150 yard limit. if it was 330 yards and i was carrying a jacketed bullet(2900fps for my 270 with a 130gr bt) i would not shoot it. because i CHOSE the 300 yard limit. years ago, i did shoot a doe, 365+/- yards away. that has been my furthest shot on a deer.

i don't regret nothing.

[Digital Dan]

Dunno what drives folk's ambition and don't care a lot actually, but I'm of a mind that one can do anything with lead that can be done with jacketed bullets with very few exceptions. Terminal performance is largely irrelevant if one is shooting prairie dogs or like vermin. Precision is key, thus it becomes the Holy Grail for that pursuit. Elk, bear, moose and the like are a different story.

Lot of folks stress over drops and think that velocity is the cure, even while paying scant attention to drift. BC is the devil in that detail and drift is the wild hare. End of the day, the fellow that knows the capability of his rifle/load and self will find success if determined. As example, some time back there were some Indian chiefs overlooking affairs at Adobe Walls. Crazy Billy Dixon sent them packing. Well, all but one of them. With black powder and lead.

Simple way to go fast with lead is the paper jacket. Applied properly to a proper bullet of proper alloy, loaded in a proper case, it will meet all performance objectives, assuming one does the homework. It will mushroom and kill stuff dead.

Tdoyka, wasn't too long ago I was shooting a Marlin 1895 CB in .45-70. 510 grains paper patched, 20:1 and 1800 fps out the muzzle. It shot MOA 7 days a week. There was no confusion about whether or not it had gone off when you jerked the trigger.

I would not be inclined to shoot paper patch from a .308 myself, mostly because it has a short neck and I don't own one. OTOH, I have shot paper patched round balls, so who knows???

Dan

PS: They shot really well by the way. Right up until around 2400 fps (chronographed), but I have no idea where they went. Down below 2200 fps they were hovering around MOA at 50 yards. Pure lead it was.

[ammohead]

The point why a man would use a cast boolit to hunt is pretty much the same as using archery equipment. It adds another dimension to the pursuit. Antelope is considered to be somewhat of a long distance situation out west and yet Nevada issues archery and muzzleloader tags to take antelope and they all get issued with none left over. A 308 with cast boolits has it hands down over any compound bow and has an advantage over most muzzleloaders as well, in accuracy, trajectory and lethality. If only the method with the highest firepower was an option we would all be hunting with 338 Lapuas. Vive la difference!

[xdmalder]

I have a serious case of Marlinitis. Right now I am shooting cast bullets in:

Marlin 1895 : 45-70
Marlin 1894 : Custom 45 Super
Marlin 336ER. : 356 win
AR-15. : 300 Blackout

All of the guns shoot their cast loads sub MOA. I also have a 30-30 I may cast for but have around 1500 jacketed bullets to go through. What I am trying to do is make the best bullet I can for each gun. And then stock up. I have been saying 308 all along but really am wanting a dedicated load for my custom 336 in 307 Win. I had the action lengthened to 2.69" to accept a longer bullet. Problem is with tube safe ammo I can't push it to its max. Bullets will blow up. I can use the 160 grain FTX bullet for the 308 Marlin Express but if I push it past 2650 it wants to blow up on impact. My best groups happen around 2750 and I have gotten it to 2800 with great accuracy. I may just end up go with a Hawk bullet for it.

Right now I am in the beginning stages of developing a cast load for the 300 Blackout. 147 grain hollow point, cup point, or solid. Has a .200 meplat. Should be able to push it to 1900+ fps but I know with cast I won't need to. As soon as NOE get their 247 grain hollow point back I will get it for subsonic use also.

[jhalcott]

Paper patching will allow much higher velocity than normal lubes. It may give excellent accuracy also.

[35 shooter]

I've got the 30 xcb boolit(166 gr.) running 2,447 fps. in my .308 12 twist 23.5" bbl.
Also have the 311299 noe boolit(202 gr.) running 2,300 fps. plus and plan to run it faster at around 2400 fps when i get some more range time this spring.
Only very minor fragmenting on nose tips sometimes when recovered from hard packed red clay and gravel dirt banks @ 105 yds. I do ht the boolits.
1.5" groups,usually much less @ 105 yds. with unweighed boolit...weighed boolits shoot a little better, usually well under an inch for 5 shots at the same range.

I did have a stock problem with this rifle, but once that was fixed, load developement went about as quick as with jacketed for me.

For speed and accuracy with cast boolits, i've found the slower powders that fill the case to be the ticket for easy load developement.
For the ranges i shoot when hunting...0 to 300 yds., there wouldn't be much of an advantage in going back to jacketed. Plus i like the
'no bloodshot meat" effect i get with cast.

Don't get me wrong, i've got nothing against jacketed, it's just that i've found i can get enough speed and accuracy with cast to flatten the trajectory enough to make me happy and have experienced no negatives in doing so.

[waksupi]

Which mold were you using

It was a Lee, I think 170 gr.

[waksupi]

Something to keep in mind in the search for speed. Look at ballistics tables. Once you find an accurate load, you need to increase the speed by 300 fps to make any appreciable flattening of trajectory. Not worth the effort, unless you just really enjoy load development like some of us do. If you can get to 2200 fps, you are pretty maxed out for performance requirements, unless you want to go post-graduate level.

[TXGunNut]

Just because a cartridge is capable of or developed for relatively high velocity doesn't mean a CB hunting load in that cartridge needs to go fast. I'm in the process of developing another CB hunting load for 30-06 for my rifle. I worked up a very low velocity/low recoil load for a youngster using that cartridge last year and it worked great! Some critters in some situations don't take much to kill cleanly, it certainly doesn't take a 165 gr jacketed bullet @ 2800 fps to kill Texas deer.

[jhalcott]

I am reluctant to shoo tgame critters beyond about 200yards. Too many game thieves around these days. I have mobility problems,by the time I reach MY deer, some one else might be claiming it.. . I have used soft nosed/lino bodied cast bullets for game and varmints. In calibers as small as .223 and up to 45_70.They can work very well IF bones are not hit. My normal muzzle velocity with ACWW alloy is about 2200fps. In the 45- 70 it is less than 1700/rifle 1350 in the Contender.

[6pt-sika]

I'll find out first hand this summer in the accuracy department . And if I can get the gun to shoot to suit me I'll find out about the deer killing ability in the fall . I have a couple molds coming for my new to me Mannlicher Schoenauer MCA 270 . I'm gonna try loads in the 2400-2600 FPS range . I also plan on trying air cooled and water dropped WW's . I have some 50/50 pure/WW alloy as well I may try .

[white eagle]

IF I have a rifle that is a speed demon say like my 220 swift
I don't even consider using cast
there are rifle cartridges that are more suited for cast velocity wise
of course you can always down load speedy cartridges if you so desire

[popper]

xdmalder - SIL has a 308ME - very accurate. He go one a while back with factory FTX, hit the spine and it blew up. But then his his kid got one with a 243 SST and it blew up too. Both were ~100 yds. Dverna & D.D. have it right, use the jacketed stuff for really long hunting shots. Accuracy counts. I took my AR carbine pig hunting (2400 load) but saw nothing but deer, got a pig that trip with 40SW cast @ 25. My BO is doing 2100 with a 145gr PB FP, try H110/296. Not a fps freak but those critters move fast and even close I want flat traj. for a good hit. Buddy tries to get running hogs with his AR15 @ 150 or so. He gets hits but doesn't drop them.

[nanuk]

.....

For me, cast rifle bullets used for hunting have their place in slower and heavier applications. Where a long shot is 200 yards. Limit the range with your .308 if that suits you, but you will regret it the first time you have a 350 yard shot down a power line or across a corn field.

Don Verna

that's where "Hunting" skill comes to play!

[sixshot]

Just make up some soft nose cast slugs, takes a bit of experimenting but works great once you hit the sweet spot. I use 2 different casting pots, the one with pure lead I just use a small dipper to pour in the pure & then top it off with my WW alloy & then water quench in a bucket of water that has a towel in the top. The towel has a small hole in the center so the bullet roll to the center when cool & drop to them bottom. You don't need a lot of them, unless you're from Utah.

Dick

[runfiverun]

:groner:
l.m..b.o. Dick.

[Oklahoma Rebel]

adding copper to your alloy will help at higher velocities both to grip the rifleing and keep the boolit from breaking up, I made 125lbs of 5/4/.5copper

[Oklahoma Rebel]

it was lyman #2 but I know the copper replaces some tin in the alloy so 4% tin is a guess, it is between 4 and 5%

[trapper9260]

How would you add copper to your alloy mix. Is it a powder?

[Larry Gibson]

If your rifle has a groove diameter of .308 and you're pushing the cast, lubed bullets 1700 - 2000+ fps the bullets are being swaged down not only by the bore but by the layer of lube in the barrel. Recovered bullets cast of #2 alloy and WQ'd out of .308 barrels measure .303 - .305 most often. The harder the alloy the less this swaging occurs but the bullets will still be less than groove diameter. Thus how well the bullet "grips the rifling" is more a function of the depth of the rifling than the alloy. Recovered bullets out of 10, 12, 14 and 16" twist barrels with .004 deep rifling at velocities of 1700 - 2900+ fps show no evidence of stripping in the rifling.

Another associated problem with adding copper to a ternary alloy such as #2 is that shrinkage in the mould is increased. Since we can not control the shrinkage to ensure it is even on the bullet such copper alloyed bullets are more unbalanced. At higher velocity those imbalances are very detrimental to accuracy. The inaccuracy is much more pronounced at longer ranges, especially at ranges longer than 100 yards.

Having killed numerous animals with cast bullets at 1950 - 2200+ fps the break up or shattering of a ternary alloy cast bullet is more a function of the bullet design than of the alloy.

Larry Gibson

[runfiverun]

except that copper makes a cast boolit grow just like antimony after it is out of the mold.
imbalances from diameter differences are from out of round molds, uneven heat distribution, or heating the mold to a point where it expands towards the cavity's while casting.

[MT Chambers]

If not for cast bullets in our .308s and others, many of us could not afford to shoot them.

[robg]

If not for cast bullets in our .308s and others, many of us could not afford to shoot them.

True for me

[Larry Gibson]

except that copper makes a cast boolit grow just like antimony after it is out of the mold.
imbalances from diameter differences are from out of round molds, uneven heat distribution, or heating the mold to a point where it expands towards the cavity's while casting.

Not at all in my experience. The moulds (Lyman, MiHec and NOE) I tested copper+ ternary alloys in produce almost perfectly round bullets with COWWs +2% tin, #2 alloy and linotype. Casting with Copper+ alloys does require a bit different casting technique. The problem is with bullets having more shrinkage, even if they do expand again, you can not control the shrinkage or the expansion. Also the imbalance does not have to be very large can be as small as in the 10 thousandth range, to create a greater degree of inaccuracy at higher velocity/RPM. It's the difference between moa or less accuracy and 1 1/2 - 2 moa accuracy. Or, if you push the unbalance to hard by velocity/RPM it exceeds the RPM Threshold.

Larry Gibson

[Hamish]

This is the first time I've heard anyone report shrinkage with added copper instead of growth, for up to two months. The more copper, the more growth.

Guess I shouldn't be surprised.

[Larry Gibson]

The Copper + alloys shrink in the mould when the alloy solidifies. My old 311466 drops Lino bullets at .313 and the copper+ alloy at .311. It's why most old Ideal and early Lyman moulds cut with older cherries drop "oversize" bullets. They were cut for Lyman #1 alloy. In moulds with the nominal diameter of 311xxx they would drop close to .311 bullets with that #1 alloy. Any guess what #1 alloy was? It was 80 parts lead, 10 parts tin, 7 parts antimony and 3 parts copper.

That's why Copper+ alloys will drop at smaller diameters, they shrink more in the mould. Should be no surprises there.

Larry Gibson

[jhalcott]

I've tried a LOT of different BABBIT alloys mixed with lead and other bullet alloys. Some times I had to wonder WHY that mix shot so poorly compared to another similar. In a few cases it was the copper in the babbit. A very similar alloy with a good bit LESS copper, was much more accurate. I got some bullets made from an aluminum/zinc mix. They weighed a lot less than the normal cast boolits from identical molds. They were much harder also. If shot at starting loads for jacketed they were okay accuracy wise. They would NOT expand at these high speeds. They would foul the barrel quick too.! I shot five or six at ground hogs one day, the next day at the range I could not hit a ten inch plate @ 100 yards. NO amount of cleaning helped! A rebarrel job was done. Those slugs would zip thru a ground hog as if it wasn't there. A head shot popped the eyes on one but the entry/exit holes were the same size. Heart shot, the piggies would stand up , look around , then fall dead.Any gut shot hog would run to its hole.

[Oklahoma Rebel]

not sayin it doesn't happen, but I have never noticed any shrinkage, or imbalance, my Cu boolits are as or more accurate then regular #2 alloy boolits. I use a stick welder and thick copper wire to get the copper in, I "weld" on the frequently stirred surface of molten lead in my large half propane tank smelter. I judge by weight as to hhow much to put in, that is easier if you do a large batch. mine was 125#and I think like ten ounces of copper. but its been a while so not sure

[MostlyOnThePaper]

How would you add copper to your alloy mix. Is it a powder?
Adding babbitt with copper in it is the most reliably/repeatable way.

You get a harder yet more malleable bullet, not brittle.

[MostlyOnThePaper]

This is the first time I've heard anyone report shrinkage with added copper instead of growth, for up to two months. The more copper, the more growth.

Guess I shouldn't be surprised.
Nor should you be surprised we have to hear the RPM Threshold nonsense yet again.

Claiming shrinkage when the rest of us that have actually tried it KNOW it grows makes it seem as though he hasn't really tried it.

Pretty good example of why I don't spend much time here anymore. It's a shame, used to be a good forum.

Sent from my SM-G930P using Tapatalk

[Harter66]

Is there a possibility of using a spitzer style bullet for hunting and shooting at a velocity of 2400 fps to get the range and the bullet to perform terminally and down range

If your rifle will shoot the NOE 312-230 FP my Strelok calculator predicts just over 1000 ftlbs at 100 yds with a 1700 fps muzzle speed .

[Larry Gibson]

If your rifle will shoot the NOE 312-230 FP my Strelok calculator predicts just over 1000 ftlbs at 100 yds with a 1700 fps muzzle speed .

Pretty much how I actually figured my max range with cast; accuracy along with maintaining 1500 fps at that range also for sufficient energy and terminal performance.

Larry Gibson

[NoAngel]

I use copper babbit added to wheel weights as per the recipe given to me. A 230g Thor fell from the mold at .360 and after sitting for several months measure .361 on all I checked.

Same mold with straight ww's gave me .359

Any Cu enriched alloy I've used has added at least a thousandth or two to the diameter.

[NoAngel]

Nor should you be surprised we have to hear the RPM Threshold nonsense yet again.

Claiming shrinkage when the rest of us that have actually tried it KNOW it grows makes it seem as though he hasn't really tried it.

Pretty good example of why I don't spend much time here anymore. It's a shame, used to be a good forum.

Sent from my SM-G930P using Tapatalk


How dare you blaspheme the holy gospel!!!

[Oklahoma Rebel]

I DO love copper as a grain refiner,it seems almost magic that it (the boolit) can be as hard as it is, yet still deform/expand at somewere between 1500-1700 ( I don't have a chronograph). I have needed one for a while, but its not at the top of my priorities, need to check garage sales. I never see them in th S&S forum

[NoAngel]

I DO love copper as a grain refiner,it seems almost magic that it (the boolit) can be as hard as it is, yet still deform/expand at somewere between 1500-1700 ( I don't have a chronograph). I have needed one for a while, but its not at the top of my priorities, need to check garage sales. I never see them in th S&S forum


Magneto-speed.

Worth every penny. It mounts to the barrel and unless you're real clown, you can't shoot the thing and destroy it. It's also not light sensitive. No sunshades or rigging up cardboard to shade the thing. It's been a real blessing to me.

[Oklahoma Rebel]

huh, I didn't know about having to shade chronographs, but I have heard of people shooting theirs. that's the kind of thing that is hilarious..... until it happens to you.lol thanks for the tip, are they expensive?

[NoAngel]

http://www.magnetospeed.com/products/chronographs/


This is the one I have.
https://ads.midwayusa.com/product/628777/magnetospeed-v3-ballistic-chronograph


THey have a cheaper model. I don't think it comes with as many spacers and the computer looks different but would be just fine if you can't justify the cost of the V3

https://ads.midwayusa.com/product/896627/magnetospeed-sporter-chronograph

[Oklahoma Rebel]

those are cool! maybe I can find one used on ebay sometime. thank you for the info

[texasnative46]

To All,

I strongly suspect that ANY of the .30 caliber or larger caliber rifle rounds (that are large enough to contain that much powder) are perfectly suitable to take most any American/Canadian game animal with a 180 or heavier grain GCCB bullet at 2,000FPS. = MANY a large bear in AK, elk, moose & even BIGGER/FIERCER GAME like TIGERS & GAUR have been successfully taken with a S-A War vintage US Krag government load of a 200 or 220 grain FMJ bullet of "cupro-nickel" at 2000 FPS.

just my OPINION, satx

[Oklahoma Rebel]

possible and suitabl are two totally different things though, a circus elephant was once killed with a 22. hard to believe but it happened

[assasinator]

Nor should you be surprised we have to hear the RPM Threshold nonsense yet again.

Claiming shrinkage when the rest of us that have actually tried it KNOW it grows makes it seem as though he hasn't really tried it.

Pretty good example of why I don't spend much time here anymore. It's a shame, used to be a good forum.

Sent from my SM-G930P using Tapatalk



i am late on this thread, but....

i use certified copper babbit with other metal added for a full magnum load in my 350 remington magnum....


the goal was the lightest, toughest cast boolit possible. lots of tin and very little lead. i waited months to size them.

i am currently considering a 358 STW barrel. that same LONG 280 grain mould will come in handy with babbitt boolits. i think they are 1.208" long, .439 B.C.

they shoot great at 2400 fps with that little cartridge. the average weight was 247 grains from a 280 grain mould.

[badgeredd]

i am late on this thread, but....

i use certified copper babbit with other metal added for a full magnum load in my 350 remington magnum....


the goal was the lightest, toughest cast boolit possible. lots of tin and very little lead. i waited months to size them.

i am currently considering a 358 STW barrel. that same LONG 280 grain mould will come in handy with babbitt boolits. i think they are 1.208" long, .439 B.C.

they shoot great at 2400 fps with that little cartridge. the average weight was 247 grains from a 280 grain mould.

If one uses a high tin babbitt (popularly called Genuine Nickle Babbitt, which does not contain nickle but is fairly close to the same color as nickle) and an alloy calculator, he can add the babbitt to a lead/COWW alloy and get heavier bullets that will react well to high pressure/velocity while remaining malleable. One's goal should be a balanced alloy with about 2 3/4% antimony. By balanced I mean, the percentage of antimony equals ( or nearly so) the sum of the copper and tin. That relationship in the alloy has been working for me for several years. The bullets will stabilize in size and hardness in about 2 weeks. If they don't, the alloy has too much imbalance and is likely high in tin. My experience...hope it helps those that want to try it for their selves.

Edd

[Larry Gibson]

The shrinkage mentioned in my earlier post was addressing what occurs in the mould as the alloy solidifies before it is dropped from the mould. It is not in reference to what occurs at a later time as the solidified bullet ages (10 days to two weeks as mentioned). Even if the bullet size stabilizes that does not negate any imbalances in the bullet.

Also, in the example of the older 311455 mould I was referring to the use with the quarternary alloy Ideal #1. That has considerably more Cu in it (10%) than the alloy badgeredd recommends. I use the babbitt badgeredd sent me some years ago and have found his recommended percentages to make a good, malleable alloy as he states. It is unfortunate some let their personal dislikes cause them to misconstrue what is said. The fact they are getting good accuracy above the RPM Threshold as discussed by me is because I was discussing it in relation to the use of a ternary alloy such as COWWs and #2 alloy. The use of a quarternary alloy with copper in it as mentioned in this thread does raise the RPM threshold level above that for a ternary alloy. Still there is an RPM Threshold (albeit a higher one) with the quaternary alloyed cast bullets also. That is still the reason accuracy does not hold as high as with jacketed bullets. The velocity level where accuracy is lost is also the RPM Threshold.

I have proven the RPM Threshold by pushing a ternary cast bullet to 2900 - 3000 fps and maintaining 1 to 1.35 moa out to 600 yards.

If the mentioned 2400 fps with 350 Remington magnum was with a factory barrel then it was probably a 16" twist if in a Remington. If so that is only 108,000 RPM.....well below the RPM Threshold for a ternary alloyed bullet. It should have proved accurate. FYI; in a 14" twist it is still below the RPM Threshold and in a 12" twist it would be at the top end of the RPM Threshold.

[vzerone]

The shrinkage mentioned in my earlier post was addressing what occurs in the mould as the alloy solidifies before it is dropped from the mould. It is not in reference to what occurs at a later time as the solidified bullet ages (10 days to two weeks as mentioned). Even if the bullet size stabilizes that does not negate any imbalances in the bullet.

Also, in the example of the older 311455 mould I was referring to the use with the quarternary alloy Ideal #1. That has considerably more Cu in it (10%) than the alloy badgeredd recommends. I use the babbitt badgeredd sent me some years ago and have found his recommended percentages to make a good, malleable alloy as he states. It is unfortunate some let their personal dislikes cause them to misconstrue what is said. The fact they are getting good accuracy above the RPM Threshold as discussed by me is because I was discussing it in relation to the use of a ternary alloy such as COWWs and #2 alloy. The use of a quarternary alloy with copper in it as mentioned in this thread does raise the RPM threshold level above that for a ternary alloy. Still there is an RPM Threshold (albeit a higher one) with the quaternary alloyed cast bullets also. That is still the reason accuracy does not hold as high as with jacketed bullets. The velocity level where accuracy is lost is also the RPM Threshold.

I have proven the RPM Threshold by pushing a ternary cast bullet to 2900 - 3000 fps and maintaining 1 to 1.35 moa out to 600 yards. I am at the point where I am going to try quaternary alloy 30 XCB bullets using the alloy mix badgeredd recommends. I will test it in 10, 12 and 14" twist .308Ws and a 16" twist 30x60 XCB. By comparing the velocity/RPM point at which accuracy is lost with each twist rate will tell us where that RPM Threshold with that quaternary alloy is.

If the mentioned 2400 fps with 350 Remington magnum was with a factory barrel then it was probably a 16" twist if in a Remington. If so that is only 108,000 RPM.....well below the RPM Threshold for a ternary alloyed bullet. It should have proved accurate. FYI; in a 14" twist it is still below the RPM Threshold and in a 12" twist it would be at the top end of the RPM Threshold.




Larry you've proven nothing concerning your threshold with the 30 XCB at 2900-3000 fps providing that the rifle you shot it in I believe has a 16 twist so that makes the rpm 135,000 which isn't no ways out of your theory range. Make note too that you used a "fitted" bullet which brings up to your theory test done with non fitted bullets of mediocre design and of bad casting which you yourself have admitted in not only a recent thread in the Cast Boolit section in which I told you that you can't do an accuracy test of different twists with cast bullets because they aren't nearly perfect enough no matter how well they are cast. Your rpm and twists tests are flawed. Couple that up with Bryan Litz saying you can't use three different rifles no matter how close they are to one another. You read it.

I'm not arguing with nor trying to run you down. Too many people here have pushed well beyond your threshold with accuracy which you keep moving up. A threshold is the magnitude or intensity that must be exceeded for a certain reaction, phenomenon, result, or condition to occur or be manifested. In your case that certain reaction is very bad accuracy or bullets flying wild. Your threshold is a set thing, one can't keep pushing it up. I surmise that you wish you never came up with that theory because it's coming back to bite you in the back end.
Are you positive that the ternary alloy you speak of so often is indeed only lead, tin, antimony and does not have any other elements in it such as zinc, arsenic, aluminum, copper, to just name a few? If you are how so?

[Larry Gibson]

"I'm not arguing with nor trying to run you down."

Who are you trying to kid.......

"Too many people here have pushed well beyond your threshold with accuracy which you keep moving up."

No they have not. They have pushed it up just as I said years ago and have repeatedly demonstrated it could be done. "A threshold is the magnitude or intensity that must be exceeded for a certain reaction, phenomenon, result, or condition to occur or be manifested." That is absolutely correct; exceed that condition and inaccuracy results, especially in a non-linear fashion as the range increases. However, your once again incorrect assumptions of what I mean are, in fact, incorrect. The inaccuracy does not have to be "very bad accuracy or bullets flying wild." It can simply be those uncalled flyers a bit out of the group. Also a sure indication is simply non-linear group expansion as the range increases. The RPM Threshold is not biting me at all but it sure does irritate you and some others. I never said the RPM Threshold was "a set thing". YOU, as you or as your "cuz", have continually said it was a "limit" even though I have said from the very beginning it was not a "limit" but that it could, in fact be pushed up or down.

Your inane accusations of me using poorly cast bullets that were not "fitted" is also a blatant lie. You really need to quit using that because everyone sees it for what it is. I never ran a test with "non-fitted" bullets. All were sized/fitted to fit the throats. The 311291 I used in the initial test was also used by myself and another member in 10" twist 30-06s demonstrating pushing the RPM Threshold up with 1 1/2 moa accuracy into the 2100 - 2200 fps range. I also have used the 311466 and 30 XCB bullet in 10" twist .308Ws and 30-06s with SAAMI or M118/M72 match chambers to 2350 2400 fps with the same 1 1/2 moa accuracy and done it with 10 shot groups. recently I demonstrated to waco such accuracy at 2365 fps out at 500 yards from a 10" twist .308W with a M118 chamber. Nothing was "fitted" beyond sizing the bullet to the chamber throat.

If there is not an RPM threshold then how is it most cast bullet loads with fast and medium burning powders lose accuracy when they exceed 140,000 RPM......How come you nor no one else shoots cast bullets of binary (lead and tin), ternary Lead, antimony, tin) or quarternary (lead, antimony, tin, copper) alloys out of a 10" twist .308W or 30-06 at jacketed velocities with equal accuracy? If there is no RPM Threshold how come accuracy does sometimes go very, very bad very, very quickly above a certain RPM? Yes, the RPM Threshold is well proven regardless of what you "surmise".....

[Preacher Jim]

I think you fellows need to realize I am reading this thread and I feel all of you are entitled to express your theory but the running another person's theory down will stop now. Go prove your theory post your finding and leave the nitpicking one another out of cast boolits.

[Larry Gibson]

Thank you,

[vzerone]

So you say they have pushed it up. Let's take a rifle and caliber that has defeated you and one that you have recently posted about in at least two forums. The 6.5x55 Swede. You even said you are going to reside to shooting the 1400 to 1800-1900 fps with it and be happy. Now my "cuz" flat out beat your threshold with his Swede using the 130 Kurtz bullet. I'd say a 1/2 inch group at 100 yards at nearly 2300 fps in that fast twist isn't just pushing up the threshold. You do realize that a threshold is no moveable, or least by not much? How about a door threshold? Ever stop to think why it's called that? Before you address the above Swede shooting that test was repeated many times, just not photographed nor talked about. Also not photographed or talked about is the 180 grain 30 Sil at jacketed velocities into very small groups none larger then 1/2 inch and out of both 10 twist, 11 twist, and 12 twist. 45 2.1 has been doing it regularly out of the Ruger Scouts. Cuz actually saw that happen and also shot almost the same small groups with it.

Here's another recent shot rifle that just didn't push up your threshold, but soundly beat it again:
Rifle: 1909 Argentine
Groove: .3110
Brass: 30-06 Rem sized down to 7.65 Argentine with no special work done to it.
Powder: Alliant RL-22
Charge: 45.0 grains
Primer: CCI Large Rifle Standard (I don't like them)
Temperature: 44 Degrees
Humidity: 43%
Wind: Less then 5 mph head on.
Attitude: 2200 feet
Shots Fired: 10
Average Velocity: 2239 fps
ES: 68
SD: 25
Group Size: 1 inch
Lube: Soap Lube
Gas Checks: Hornady
Chrono Distance: 9 feet 1.5 inches

Then their Cuz's little SAKO 7mm-08 shooting the LEE 130 grain bullet (a non-fitted bullet) into 3/4-1 inch groups at 2640 fps.

You have a selective memory Larry.

I will address your "If there is not an RPM threshold then how is it most cast bullet loads with fast and medium burning powders lose accuracy when they exceed 140,000 RPM" That's a well duh question. To reach that rpm range you have to hit the bullet pretty hard and you know very well that the fast powder is especially not the one to do so with. Do I have to tell you why? So according to you all fliers are because of the threshold? You ever think that those fliers may be from poorly cast bullets. That brings up the member casting better then your 1.1 grain variance in recent posts in more then one place on this forum. You know very well that there are many things that can ruin or prevent a bullet from starting straight into the bore.

Waco done very well for being a young fellow and with a mediocre rifle (not so much the rifle, but it's terrible throat) for the first time out doing this.

Let me know when you can cast all your bullets within a .1 grain variance. Don't forget you're the one that posted your variance weights in three forums that I know of, so I'm not making inane statements....you made them.

[vzerone]

I think you fellows need to realize I am reading this thread and I feel all of you are entitled to express your theory but the running another person's theory down will stop now. Go prove your theory post your finding and leave the nitpicking one another out of cast boolits.

You can't prove that theory with cast bullets Preacher Jim, they just aren't perfect enough nor strong enough no matter who casts them. I would never ever attempt those tests with cast bullets and we all know the reason why. None of the things I posted are lies and most the data was posted by that person. I reckon Bryan Litz isn't good enough to hear that you can't do the three rifle twist with your rifle, a friends rifle, and a third friends rifle.

[vzerone]

I forgot to say I'm done.

[Larry Gibson]

The 6.5 never defeated me. I thoroughly tested it and was quite pleased with the results. The velocity level I shoot it at now (I currently have three 6.5 Swede's, all with military barrels) is the one where the best accuracy is found and simply because that is what I choose to do. Accuracy is all I'm concerned about with cast in the 6.5 Swede because, other than for small game, I won't hunt with it so velocity is not any issue. Joe, who you call your "cuz", did not prove anything as no one else could duplicate the velocity or the accuracy he claimed. I duplicated his load with his own bullets (he sent them to me) and still fell almost 200 fps short in velocity. Here is a picture of the 100 and 200 yard 10 shot groups. Note the non-liner group expansion between 100 and 200 yards demonstrating that, even at the much lower velocity, than he claimed the bullets were over the RPM Threshold. Joe always claimed 5 shot groups accuracy but at 100 yards that still isn't bad. Defeated.......hardly.

219822


We have been hearing about “bug hole groups, not larger than ½” and moa” for a long, long time from you and the others you mention for a long, long time. Yet you fail to provide any sort of proof by posting groups or at least having your “feats” of incredible velocity and accuracy witnessed by members of this forum who have requested to do so. Lot’s of typed out claims but little or no actual documentation. I have had an open invitation for anyone to come and see me shoot and to shoot my rifles. There have been numerous CBF member come here and shoot my rifles and see what really can be done with cast bullets at high velocity. I have also won several CBA military rifle matches the last couple three years including two state matches. If you can in fact shoot such such a 1” group with your M909 you could be a national CBA champion. But both your “cuz”, 45 2.1 and several others have been told that and asked to compete. All sorts of reasons why they wouldn’t though and I’m sure you’ll also tell us why you can’t……..

Who says a “threshold” can’t be moveable…….you just makeup definitions to suit your own purpose. A threshold can be moved. A threshold definition I used when I coined the term for this application is simply, according to Webster’s, “the point at which a physiological…..effect begins to be produced”. That being the loss of accuracy due to the adverse effect of centrifugal force on imbalances in the bullet in flight. BTW; Litz agrees.

My memory is not selective. I deal with facts as presented by actual testing. Here is the 311291 in a 10” twist .308W using 4895, a medium burning powder, at 1850 fps (under the RPM Threshold) at 50, 100 and 200 yards. Notice the almost liner group expansion.

219825

Here is the same except the velocity is 2350 fps. Note the poorer accuracy and non-linear group expansion evidenced because this load is way above it’s RPM Threshold. There’s your “wild” bullets that are, in fact, over the RPM Threshold BTW.

219826219827

Now here’s using a properly designed cast bullet for HV and a slower burning powder in the same rifle which has a M118 chamber and other than sizing to the throat neither bullet was “fitted”. The velocity of this load is 2267 fps out of the very same .308W rifle. This load was also the one used to shoot 2 moa ten shot group at 500 yards. Thus is also holds linear group dispersion and is not above it’s RPM Threshold even though the RPM is 163,300. It still hold sub 1.5 moa up through 2350 fps, however, when loaded to 2400 fps I get the same 30% “flyers” opening the group to 2+ moa at 100 yards that Waco got. in the 2300 - 2400 fps range is where this load with the slower burning powders goes over its RPM Threshold. Jacketed velocity for a comparable 165 gr jacketed bullet would be 2650 – 2700 fps.

219828

Thus even though I have pushed the RPM Threshold up it still does not equal jacketed bullet potential. Neither did your “cuz’s” 6.5 loads. Here's the 100 yard and 200 yard accuracy with the 6.5 bullets "cuz" sent me with his exact load out of the M96 even though it produced almost 200 fps less than he claimed. I was certainly impressed.......[smilie=1:

219823219824

These test results are representative of the many, many test results I have posted which demonstrate the RPM Threshold is, how it adversely affects accuracy and clearly demonstrates how the RPM threshold can be pushed up, exactly as I have said for several years now.....

[Preacher Jim]

theory's, they are just that until people we do not know duplicate our results.
I buy my Krieger barrel blanks 5 at a time 2 are bug hollers, 3 I sell as varmint barrels. I have found that the average rifle if you line up 5 and use the same exact ammo will group differently. the factors that determine duplicating what is posted here are close to impossible because of several factors, 1. brass differences, barrels, powder lots, bullet mold variations. lube sizer die differences, humidity, wind, temperatures, and most of all the fellow who pulls the trigger.
in many ways the debates on all these theories boils down to I say, all of you have good information that should help a newbie in pursuit of better shooting but you destroy that with the personal attacks and arguments. Jack Webb used to say," just the facts mam". fellows report your research admit it is just what you found with your shooting and leave the proof to those who follow in your footsteps to prove.
you can quote whoever you want to enhance your theory but it is not gospel till it stands the test of time.
RPM is a proven fact, it you over rotate a round object any imbalance causes wobble or instability to surface. Where is the threshold, where it occurs. All bullets are different, I can try hard to find the sweet spot for my boolit or bullet but guys your finding will differ with your bullets.
enough said. stop the nonsense and help the ones coming behind us to shoot better.

[popper]

I haven't been able to notice/measure ANY change in dia. when using Cu in the alloy - but I don't have any tin in it. I sent some alloy and some 31-165B to Waco to test but haven't heard anything yet. Hopefully he will test the XBC & 165B in his rifle. I sent him some PCd too.
300BO carbine: Hornady 150SP gives 1950 & .3" c-c @ 50, 142C (1or2% Cu) is 2112 (avg 47 ES) .8" c-c @ 50.
LR308 carbine: same alloys give 2550 with H4895(appears to be peak of fps) & MOA @ 200. The 150Sp and 168 Amax do the same in the rifle LR308, 2700 fps.
As I've stated before, rotational energy (gyro precession effect) is what causes the RPM threshhold. Weak alloy, wind, bad cast - all the same.

[TXGunNut]

One thing that bothers me about this "threshold" debate is that this "threshold" is a matter of physics; the study of physics is governed by laws and these laws don't change. It's very real, whether we understand it or not. We can't move this threshold any more than we can change the laws of physics. We CAN change some of the dozens of variables that determine where this threshold is found. How we manipulate these variables (when possible) is what makes this line of conversation and research beneficial. Identifying these variables and learning how to work with them should be the focus of this debate, IMHO.
The other thing that bothers me about this debate is the personal attacks. I don't know why this topic attracts this type of behavior but I'm tired of it. As a group we have the ability and resources to do an awesome amount of research and testing but we have to wade through the personal attacks to follow an interesting topic. Let's play nice and figure out how to make better boolits, OK?

[Larry Gibson]

"We can't move this threshold any more than we can change the laws of physics."

Depends on how we define the "Threshold". In this instance if we want to give the Threshold a numerical number for all bullets then it doesn't move. However, if the Threshold is defined and instead based on that point where the centrifugal force causes the bullet to depart from the line of flight then the Threshold is moveable as in when we use a harder/stronger alloy, use a better designed cast bullet, slow down the acceleration time curve, put a PP on the bullet or use a copper/steel jacket on the bullet. All have a threshold, only one has a higher threshold than is obtained safely in most cartridges. It's why a 311413 cast of COWWs isn't going to be accurate at 2100 fps out of a 30-06 but the 311291 can be. It's why the 311291 isn't going to be accurate at 2800 fps out of that same 30-06 but a 180 gr Hornady SP can be.

Nothing personal intended nor am I calling out anyone. Just clarifying my own definition of the Threshold. I do not, and have never, considered it to be an absolute "limit" as many misconstrue it to be. Again, just clarification.

[Bazoo]

I've asked myself similar questions with regard to caliber.... and for that I normally stick to calibers that can deliver their full potential with cast projectiles. Im starting to be of the mindset though, that I could purchase jacketed bullets when desired or needed for longer range or more power, all the while shooting many thousands of cast bullets and enjoying the savings.

[TXGunNut]

Thanks for the clarification, Larry. I have to dumb many things down so that I can understand them. I call these things you (and others) do with alloy, design, pressures and even tighter quality control "variables" because they affect where this threshold is found. On top of that there are environmental and other variables we have no control over. I don't think this threshold is a finite number, it's a point where undesirable behavior is observed as a result of many factors. I don't pretend to fully understand the effects of all these variables but I know that you are well aware of them and are working to understand them. I appreciate what you're doing, Larry.

ETA: In other words, IMHO the destination is not as important as how you get there.

[MT Gianni]

" Merriam Webster Definition of threshold
1 : the plank, stone, or piece of timber that lies under a door : sill
2 a : gate, door
b (1) : end, boundary; specifically : the end of a runway (2) : the place or point of entering or beginning : outset on the threshold of a new age
3 a : the point at which a physiological or psychological effect begins to be produced has a high threshold for pain
b : a level, point, or value above which something is true or will take place and below which it is not or will not."

The definition of this by Merriam Webster is probably why there have been so many pitzing contest here over this. The English dictionary clearly calls a "threshold" an immovable object. If one member doesn't no wonder there has been so much confusion.

[Larry Gibson]

What I see in that definition is that a "physiological effect" or "boundary" ....."the place or point of....beginning..." As I have defined it the RPM Threshold it is that point where the centrifugal force causes the bullet to depart from the line of flight and inaccuracy begins. That point is where the physiological change in the bullets flight crosses a boundary where accuracy begins to fail and inaccuracy begins. If you change the variables as I mentioned in the prior post you can change the threshold, "boundary" or whatever you want to call it.

Eight+ years ago I was asked, no I was goaded, into naming my "theory" (I didn't then and still don't think the theory is mine because I simply began to understand it from reading what other(s) said about it years ago). So I named it the RPM Threshold just to satisfy the dissenting members here. Now after 8+ years some of you dissenters want to argue the semantics of the name........ why don't you do something constructive and prove the theory itself wrong with actual testing instead of just criticizing the name? You all don't like the name? Fine with me, it's easy enough to rename.....how about the "RPM Moveable Boundary Theory"? How about the "Point Where RPM Causes Inaccuracy"? How about the Cause of Inaccuracy in the Best of our Cast Bullets"? Will any of those name changes or any name change have any affect on any bullet in flight? No it won't change a thing. Point is we can argue all the semantics we want, change the name, etc. but that does not change the fact of what actually occurs to a cast bullet in flight.

Hey, as Preacher Jim said; "fellows report your research admit it is just what you found with your shooting and leave the proof to those who follow in your footsteps to prove." I have reported my research many times over the last 8+ years. Anyone having any research, of actual test results, of any ternary alloyed cast bullets (that's a lead, antimony, tin alloy with possible inconsequential traces of other elements like COWWs, #2 alloy or linotype) that proves me wrong we'd all like to see the actual results?

[TXGunNut]

With apologies to Larry I'd like to say I think the 3b definition cited above fits Larry's observations. I think the mistake we make is that we want to know if a boolit at X velocity with a twist rate of C is exceeding the RPM threshold. As I understand it the correct answer is "yes", "no", or "it depends...". It wasn't my intention to attack Larry or cast aspersions upon his excellent work. I just wanted to encourage constructive debate on the subject and I'm truly sorry if I didn't come across that way.

[Larry Gibson]

TXGunNut

No need to apologize, Your posts have been insightful and helpful to the conversation. When I first developed the RPM Threshold 8+ years ago it initially was based on the use of traditional cast bullets of a ternary alloy (COWWs was the alloy most used and discussed back then) loaded with fast to medium burning powders from, say, Unique up through 4895 in burning rate. It's with those the where the original RPM Threshold generally is between 120,000 and 140,000 RPM. No limit there just general figures with a potential +/- of 20,000 RPM. That's where the "yes, no or it depends" comes into being.

Some think I dreamed the Threshold up all at once and it was locked in stone. I didn't and it wasn't. I had been pondering and testing for numerous years based on reading over the years before. I didn't know every thing about the threshold then (several other cast bullet shooters have been actively conducting tests also) and we have learned a lot since then. There still is a lot to learn. The more we tested the more we learned how to push the Threshold up....or down. We learned through extensive testing of ternary alloy cast bullets just how fast we could push them, in numerous various twist rifles, and maintain linear accuracy at extended ranges......now out to 500 yards (with a 10" and 14" twists) maintain 1.5 to 20 moa accuracy and 600 yards with a 16" twist while maintaining 1 to 1.5 moa accuracy.

Now there has been sufficient testing done in the development of quarternary alloy cast bullets that we are interested in seeing how far we can push the RPM Threshold with those using badgeredd's alloy. Disregarding the quibbling the last 8+ years it has been a very interesting learning journey. I'll be headed to Montana the end of the month for some PD shooting.......mostly with two 223s and a 22-250. However, I'm taking my 30x60 XCB along to give it a try with the 30 XCB bullet at 2900 fps. Should be interesting to see the results. When I get back I plan on casting some quarternary alloy bullets (30 XCB, 311466, 311291 and 45 2.1s 30 Sil) and testing them.

[TXGunNut]

Thanks, Larry. I don't understand all you (and others) are doing on this threshold project but I have a basic understanding of physics. And I agree, you didn't invent the threshold or whatever folks choose to call it. The laws of physics have been around forever and will govern the actions of inanimate objects long after we're gone. You recognized and sought to further define this threshold. People have been dealing with this threshold since they discovered a soft heavy metal made a better projectile than a random rock.
Carry on! I'm not sure how I can use your quarternary alloy boolit performance data to improve the performance of my hunting boolits but I'll step back into lurk mode and try to learn something.

[TXGunNut]

Is there a point to using cast with cartridges such as 308 win since it is capable of so much more velocity than what can be utilized with cast hunting velocities. I know people have gotten velocities with bullets that match jacketed velocities but in hunting wouldn't they just fragment heavily on impact

My apologies for continuing the hijack of your thread. To address your question there is indeed a point to using cast boolits in cartridges designed for J-words. First of all you'll be using a boolit YOU made and there's nothing like the feeling of attaining a clean kill with a boolit you made. The fragmenting issue is an alloy issue. It's easy enough to address but others here (Fryxell, Gibson, et al) have addressed it much better than I can. Lastly boolits perform and transfer energy (shock) differently than J-words. A cast boolit does not need to achieve the same velocity as a J-word to perform adequately on game. Quite honestly I prefer boolits in a larger caliber than .308 but I know they work given the proper boolit design, alloy and of course, shot placement.

[Larry Gibson]

Interesting to note there is a sticky at the top of this sub-forum started by Dan Walker [http://castboolits.gunloads.com/showthread.php?214124-Velocity-threshold-for-cast-rifle-boolits]. He uses the term "threshold" also but I see none of the critics questioned the use of that term there......[smilie=b::groner:

There are several posts in that thread/sticky regarding RPM. In post #17 I explain, again, the RPM Threshold. My definition has not really changed since then. That was 4 years ago. Still in that 4 years we have learned a lot about pushing ternary alloyed cast bullets to true jacketed bullet velocities. It would be refreshing to hear from others who have run into the RPM Threshold with traditional cast bullets using 7" to 12" twist rifles of any cartridge?

Back to the thread topic; I have tested #2 alloy cast 311041 bullets at an impact velocity of 2600 fps out of a 14" twist rifle in sopping wet newsprint. They did expand and some of the expansion petals did slough off but the bullets did not shatter. Penetration was 14 to 18" if I recall correctly. Even at 300 yards the 30 XCB cast of #2 alloy, when shot at 2900 fps with an impact velocity of 1800 fps +/- into the same media, there was still some expansion.

[Cosmic_Charlie]

For the kind of plinking and hunting I do cast boolits are perfect. Working on loads for a Ruger American Compact in .308 and I figure when I settle on one I will sight the rifle in at 50 yds. and call it good. Same for my 30-30 and Henry BB. Looking forward to putting a cast boolit through a perched crow and also a deer this fall, maybe a beaver or two. I like the mellow recoil impulse of 1700 fps loads. Now if I lived out on the prairie I might not mess with cast at all in rifles.

[500Linebaughbuck]

i'm like TXGunNut is, i understand basic physics( well, i do mean basic :redneck:). i kinda understand what Mr. Gibson does and i do congratulate him. its nice to see someone who does deliver cast boolits to their maximum. be it max velocity or a low speed, high crushing bone load. the RPM threshold thing is not something i should do. i'm happy with my low velocity boolits and placing them a 125 - 150 yards. the deer aren't happy, but i am. :-D Mr. Gibson, i like the work you do on cast boolits.

[popper]

THis 'theory' discussion is silly. I learned that in 3rd grade, spinning thumb tacks on the school desk. They hit something and take off at weird angles. Run them slow enough and they begin to wobble and fall over (often taking off in some direction). Unbalance with some nail polish or just blow on it - zoom. It exists (for a given boolit, fps,alloy, etc.) get over it! Does you HV boolit turn sideways @ 20ft and destroy itself (turn to dust)? I use Cu enhanced alloy (RNFP) to get HV with med speed powder, it works fine (to 200 yds so far). I will use jacketed for long range shots (usually moving pigs) as I can't gauge range that good and the better BC makes the difference in DROP (yea, fps too). Yes, I hit steel @ 200 (1700 fps?) and found one sliver of boolit. My conclusion is it 'broke' off the nose as the nose slumped. I use this terminology as from experience of a 40SW that hit stone. 3/4 of the TC nose was >0.4 but a 'proud' part was still TC nose.
Sometimes the words we use aren't quite 'correct' but the best we can find.

[vzerone]

THis 'theory' discussion is silly. I learned that in 3rd grade, spinning thumb tacks on the school desk. They hit something and take off at weird angles. Run them slow enough and they begin to wobble and fall over (often taking off in some direction). Unbalance with some nail polish or just blow on it - zoom. It exists (for a given boolit, fps,alloy, etc.) get over it! Does you HV boolit turn sideways @ 20ft and destroy itself (turn to dust)? I use Cu enhanced alloy (RNFP) to get HV with med speed powder, it works fine (to 200 yds so far). I will use jacketed for long range shots (usually moving pigs) as I can't gauge range that good and the better BC makes the difference in DROP (yea, fps too). Yes, I hit steel @ 200 (1700 fps?) and found one sliver of boolit. My conclusion is it 'broke' off the nose as the nose slumped. I use this terminology as from experience of a 40SW that hit stone. 3/4 of the TC nose was >0.4 but a 'proud' part was still TC nose.
Sometimes the words we use aren't quite 'correct' but the best we can find.

popper that spinning top isn't an appropriate analogy for the simple fact that the nose of it is touching the table. That has a major influence on what that top does. However, I do agree with you that the theory discussion is silly.

There are those, and in this thread, that see no need for HV and I can understand that. There are others who do want to explore it. So you cannot condemn either group.

VZ

[popper]

No different than air pushing on the nose of a boolit. 200+ years old gyro math. Larry and others have tried to show how to do it (HV cast), others show that it isn't always the wisest choice for hunting. Whatever!

[vzerone]

No different than air pushing on the nose of a boolit. 200+ years old gyro math. Larry and others have tried to show how to do it (HV cast), others show that it isn't always the wisest choice for hunting. Whatever!

Not arguing with you, just trying to get you to see that's still not a good explanation. The table is a hard non-moveable thing. The air the bullet goes through is entirely different. That's like an idea that was posted many years ago on this forum and that's putting a straight piece of copper wire in a variable speed drill. You spin it slow it stays straight, but the faster you spin it the more it bends until it becomes like a propeller. That's never ever going to happen to a bullet and besides the one end of the wire is anchored by the drill chuck and the rest of it can move.

[HangFireW8]

One thing that bothers me about this "threshold" debate is that this "threshold" is a matter of physics; the study of physics is governed by laws and these laws don't change. It's very real, whether we understand it or not. We can't move this threshold any more than we can change the laws of physics. We CAN change some of the dozens of variables that determine where this threshold is found. How we manipulate these variables (when possible) is what makes this line of conversation and research beneficial. Identifying these variables and learning how to work with them should be the focus of this debate, IMHO.
The other thing that bothers me about this debate is the personal attacks. I don't know why this topic attracts this type of behavior but I'm tired of it. As a group we have the ability and resources to do an awesome amount of research and testing but we have to wade through the personal attacks to follow an interesting topic. Let's play nice and figure out how to make better boolits, OK?

Lack of precision in technical terminology is a real problem on this board, one I look past, but it is the least of this board's problems.

When people from the military's finest labs get called flat earthers; when amateur theorists make obvious mistakes like calling a test barrel swollen when it was not; clearly betraying a total lack of knowledge about the spring tempering of the barrels involved... and no one here has enough knowledge to call them on it... When a certain few have unlimited license to insult... and others get banned... No I have no faith any breakthroughs or advances, or even help for the advanced hobbysts will be found here.

[vzerone]

Lack of precision in technical terminology is a real problem on this board, one I look past, but it is the least of this board's problems.

When people from the military's finest labs get called flat earthers; when amateur theorists make obvious mistakes like calling a test barrel swollen when it was not; clearly betraying a total lack of knowledge about the spring tempering of the barrels involved... and no one here has enough knowledge to call them on it... When a certain few have unlimited license to insult... and others get banned... No I have no faith any breakthroughs or advances, or even help for the advanced hobbysts will be found here.

I couldn't agree with you more. I have the knowledge, but my hands are tied by a big black ban cloud over me!!!!

[Larry Gibson]

No one is going to get banned for posting actual test results such as detailed load and test information along with resulting targets, chronograph printouts and pictures.

[HangFireW8]

Well I agree with Larry on just posting data. It's the discussion after that, that becomes hazardous.

[Preacher Jim]

I am aware non agree on many things but honest discussion without arguments are productive. Attacks because you disagree are not helping new people learn. My goal is putting information out allowing actual testing and the posting of results. What was is not what is,, if a person experimenting can not come up with close results.
I have spent 58 years pursuing a 10 shot one hole group at 100 yards. I can tell you how not to get it but not how to do it because I never have accomplished it. The thing that keeps me experimenting is no one else has either, 2 have come closer than anyone else.
Guys if you do not have 2 independent witness see how, what you do, and sign off on a target you information is not fact.

[Preacher Jim]

I am looking for information on type bullet, bnh of bullet, twist of barrel used. Larry and his work have caused me to want to test his ideas.
so far his work has been good. so I have in stock 10, 12, 14 and 17twist 308 blanks all 30" finish and 308 long neck reamer over next few months I will be playing. I only have 600 yard range here available to use to test.
thank you for information Larry.

[Larry Gibson]

Your welcome. Been PD shooting in Montana this last week. Used the 30x60 XCB one day. Killed 10 out of 15 at 200 to 300 yards. Did excellent (60 %) from 300 to 485 yards. Will post more when I get back to a computer.

[rockydoc]

Mr. Gibson, if you have written a book on cast bullets, I would like to know where to buy it. If you haven’t, I think you ought to. I think many others would agree. I like your work and your ability to explain it. Please keep it up.

[popper]

the study of physics is governed by laws and these laws don't change. well. not in the world of physics WE deal with anyway. We can measure the forward momentum and rotational momentum in a cast boolit but we are hard put to measure the 'inconsistency' in a cast boolit. Forward momentum is only slowing the projectile by air resistance. Sudden OR slight changes in angular momentum cause a change in direction! Match factory ammo & BR shooters can spend lots of $$ for 'perfect' bullets. The automated manufacturing and inspection costs $$ but there are those willing to pay for it. RPM theory is a fact, like the speed of sound but the (SoS) transitional regionis +/- 10% for ANY atmospheric conditions. No need to argue, if you want to push it, work harder - on everything in casting and loading (& shooting of course). The posted results and methods are there for us to learn.