How Bullet Coating Affects Performance

[charlie b]

So, where would one acquire swagging dies for say a bullet for a ride down a longer ungreesed barrel?

http://www.corbins.com/

[charlie b]

.......I find slower, softer, heavy for any given caliber and coating, is where I have been heading.

Yep, that is my conclusion as well. IMHO, it is the tensile strength of the lead that is the problem. Since that means lower velocity then the bullet with the best ballistic coeff would seem to be best for longer ranges. That means heavier. I've been shooting 165 and 180 and will be trying 200gn or more next to see if I can stretch out to 600yd with consistent accuracy.

But, before I do that I am going to push velocity a bit with my 180gn bullets and see how fast I can go before the groups blow up (with Eastwood light blue powder). I do know that with regular lube if they go past 2000fps the groups go south.

[bruce drake]

That Gun digest test should have used the same bullet for all of the tests of the various lubes and coatings regarding the terminal ballistics of the bullets. A difference in the lead alloys will cause a difference in whether a hollowpoint expands or shatters upon impact with the test media.

[agentwolf]

That Gun digest test should have used the same bullet for all of the tests of the various lubes and coatings regarding the terminal ballistics of the bullets. A difference in the lead alloys will cause a difference in whether a hollowpoint expands or shatters upon impact with the test media.

Mystified I am, why no other(s) had enough interest since its publishing (2016) to add to this inquiry. Dead horse kick I do, but I'm a little surprised no one in this forum yet mentioned being aware of this article prior to my whinny **** prying...I'm trying to contact the author (Brad Miller), to see if he's got any more to add to the matter.

[bruce drake]

That Gun digest test should have used the same bullet for all of the tests of the various lubes and coatings regarding the terminal ballistics of the bullets. A difference in the lead alloys will cause a difference in whether a hollowpoint expands or shatters upon impact with the test media.

[charlie b]

Maybe because it is for pistols? I know for my use in pistols the velocities are such that lead does fine. Just adjust the powder to get the velocity. For serious work I either used hard cast SWC/flat nose or I used factory hollow points. I matched the pistol to the target, ie, big game meant heavy loaded .45 Colt, small game was light loads in .357. Practice rounds were simple RN or TC bullets. I guess if you are trying to make major with a 9mm you need every extra fps you can get, but, that applies to a small number of casters. Or if you are intent on carrying a 9mm in bear country, etc.

If he had done the work with rifle bullets it might have made some impact as 'we' are always trying to get more range/velocity. Just look at the work guys are doing adding copper to the alloys just to get some extra velocity.

[agentwolf]

Huh, speaking of statistics, here's a tasty morsel of food for thought (article link below) to further muddy the already dirty waters, as we endeavor to aim at our moving target. Evidentially, all things do NOT stay equal... Casters and reloaders have been vaguely aware of this opaque truth for years, but information's travel isn't as consistent as we're to believe, and sometimes it's just lost and rediscovered. D'oh!

Ballistic Fingerprinting

[curioushooter]

Instead of talking about it why don't you just shoot some gel with powdercoated cast hollowpoints and find out?

If you want mail them to me and I will test them and post it here. Just mail me three or so. PM me with your proposal. I can test in the following calibers: 38 special, 357 mag, 357 max, 30-30, 32-20, and 9mm.

If you want to know what I think from experience with gel, I will tell you I expect PCing makes little to no impact on terminal performance. Why would it? The reason copper jackets effect performance is they are much tougher than the lead alloy core. I would think the paint is much softer than the lead alloy.

[popper]

Bama did good with his swaged PC. I did MOA @ 200 with LR 308W carbine (31-165C) PC, 2400 fps. Pick up 300 fps in the rifle upper. The BO does MOA @ 100 145gr PB PC, 2100 fps. Alloy is the limiting factor. IMHO good jax target bullets are a smidge more accurate and definitely have better BC for the longer range.

[charlie b]

Aren't you guys using copper alloy bullets for the higher velocities?

[popper]

I do but get decent with ~4% Sb, no Sn. Cu just makes it mo better with less Sb. Sulfur works good but they are messy and smelly. Used sulfur in 30/30 pushed hard,but they seems kinda gritty like you could rub the surface off - not PCd. Didn't PC any of those.

[charlie b]

Thanks.