Bullet Construction vs Lethality

[nralifer]

Just a side note: The original 5.56 round fired in a 1:14 twist M-16 BBL was deliberately designed to tumble upon hitting soft tissue to cause severe damage despite using non-expanding FMJ bullets mandated by conventions and treaties.

You are talking about the 120 yr old Hague convention which we never adopted but for some reason we adhere to in principle. That notion of using marginally stabilized bullet in the 5.56 was a mistake because those rifles could not shoot the heavier bullets. At least that concept illustrates the point that a marginally stable bullet, when it encounters flesh, which is denser than air. the bullet is unstable and tumbles.

 

[nralifer]

Really?

I can tell you that Bryan Litz knows a 1000 times more than Hammer owners do about ballistics.

 

[FEENIX]

IBTL!

 

[xsn10s]

You are talking about the 120 yr old Hague convention which we never adopted but for some reason we adhere to in principle. That notion of using marginally stabilized bullet in the 5.56 was a mistake because those rifles could not shoot the heavier bullets. At least that concept illustrates the point that a marginally stable bullet, when it encounters flesh, which is denser than air. the bullet is unstable and tumbles.

We did/ do except when it comes to the war on terrorism.

 

[Petey308]

Good question about when the spin of the bullet stops. Theoretically it can differ by the mass of the bullet. A heavy for caliber bullet shot from a given twist barrel will have more angular momentum than a lighter bullet shot from the same barrel at the same speed, so it will maintain it's rotation longer through an animal. In our gel testing we see evidence in the bullet track through the clear gel that is spirals to at least a16 inches and the heavier 338 bullets can go as far 25-32+ inches.

In so far as the blanket statement that copper bullets require tighter twists, that is true to some extent due to the fact that copper is less dense than lead (8.89g/cc vs about 10.5 g/cc). So to make a copper bullet of the same weight it has to be longer. However, in a 30 cal 1:10 twist will accommodate our 150-195 gr bullets very well, but when you get to a 205 gr bullet, a 1:8 twist is needed, so there is some overlap. That said, "over stabilizing" a copper bullet never hurts and may add to it's lethality because of the faster rotational velocity. The reverse is not always true. I have seen this problem with A-Tips blowing up in mid flight when shot out of a 1:7.5" twist barrel. Actually, I bought that barrel from him and it shot our bullets down to 1/4 moa with little load development.

To compensate use a lighter for caliber bullet. This is not a real handicap. For hunting purposes petaling copper bullets will outpenetrate lead cores even the light for caliber coppers. I have seen that over and over with Barnes and ours. In our first hunt with the first generation Bulldozers shooting 7 Plains Game animals, including a Bush Pig longitudinally through the head we recovered 0 bullets. All pass throughs. We were using a 308 Win and an MV of 2920 fps and made shots out to 500 yds.

Momentum plays a big part and a bullet that retains more weight will retain more momentum. More momentum retained means deeper penetration.

What a particular bullet may or may not have that can still reduce the momentum at a higher or lower rate is surface area in contact with the opposing force. So a mushrooming, petaling, mono will still lose momentum fairly quickly and the wider the mushroom the higher the rate of momentum lost. This is due to the greater surface area produced to the opposing force.

A lead core that mushrooms but also loses mass as it expands and penetrates will lose momentum at a much higher rate due to losing mass AND increasing surface area to the opposing force. But, if it starts out with a great deal of momentum it will still penetrate pretty deeply as a result, as it all balances out better that way. Lower starting mass or a more softer construction will lose momentum very rapidly and tends not to penetrate deeply. Depends on shot placement, animal type, etc it may not result in a poor result overall though. It will just depend. It may result in a maimed animal in some scenarios.

A mono that sheds petals sheds mass, and thus will lose momentum. But, by not having a wide surface area after shedding the petals, what remains of the bullet (the shank), and thus it's amount of mass, will slow momentum loss from that point on. It will still tend to lose quite a bit of momentum initially as it opens up and sheds the petals though.

And yes, there is still a balancing act with spinning a lead core too fast. Versions that feature thin jackets, such an an A-tip, ELDM, certain Bergers, etc and especially versions with a long bearing surface (heavy for caliber versions) will create a great deal of friction and thus heat transferred to and through the bullet. It can melt the core and compromise its structure integrity and cause them to rip apart in flight, or at the very least go off course.

Rotational forces can cause softer constructed bullets to come apart more on impact as well. It can cause petals to separate too on certain monos if spun way too fast.

There's a balancing act and it can highly depend on your particular scenario and application.

However, in a 30 cal 1:10 twist will accommodate our 150-195 gr bullets very well, but when you get to a 205 gr bullet, a 1:8 twist is needed, so there is some overlap.

Yes, the twist rate needed varies depending on length and density. Using a stability calculator with the particular bullet's dimensions will tell you what twist you need to get to the ideal SG for that particular bullet. You may need to step up the rate of twist for certain ones. You may be fine for about any weight too. You may be too much for certain other types of bullets, such as the thin-jacketed lead cores mentioned.

Length of barrel also factors in regarding amount of friction. A 30" 1:10 twist barrel will create more heat in the bullet from friction than a 16" 1:10 twist.

Bottom line is there are indeed many factors that go into it. A lot of times things match up just fine for a good outcome and we don't even have to think about all those factors. It seems simple and seems like these discussions overcomplicate the out of it lol. As long as things are balanced, it is indeed simple. If you get one or more things way out of balance though, bad things start to happen or at least things get inconsistent.

 

[ButterBean]

I can tell you that Bryan Litz knows a 1000 times more than Hammer owners do about ballistics.

And the same for you? Or are you on par with Litz

 

[Calvin45]

Dumb guy here and after pages 1-14 (with mild derailments) I appreciate the education. Stupid question but here goes. How is it that we are still mainly using lead and copper for projectiles? Where is the research on other alloys? If a titanium receiver is stronger then wouldn't it stand to reason there are stronger alloys than lead and copper? I know someone mentioned depleted uranium from a tank or anti aircraft gun, but seriously, 300 plus years of shoulder fired projectiles and we are still at lead, copper or lead and copper?

(Is this where I say asking for a friend?)

Lead really is a wonderful material for bullets that you want to expand…it's cheap, plentiful, extremely dense which is always a good thing especially regarding external ballistics as well, and it's soft and malleable. Very hard to beat.

Copper shares some of those virtues, ductile, malleable, definitely harder AND more cohesive, less disintegrating…this can be both a good thing and a bad thing. But the use of copper or gilding metal in bullets was originally about needing bullets that could survive a trip down rifling at the velocities with smokeless propellant, and it proved useful on targets as well, either in full metal jackets that enabled unprecedented penetration at high velocity or soft points that did a lot of damage via the deformation of lead WITH much greater penetration on account of the copper jacket.

There simply isn't a metal in the periodic table that is as cheap and easily workable BUT MORE IMPORTANTLY ultra dense while being soft and readily deformed for terminal efficacy as boring old lead.

And whether in monolithics or jacketed lead bullets, many have indeed tried to find something better than gilding metal or pure copper…and failed. Brass is brittle as all get out in comparison (and still a copper alloy). Aluminum is abrasive as all hell. Nickel is very slippery which is good BUT is also very very hard. Too hard. They found that with Cupro-nickel jacketed bullets back in the day. Nickel plated copper seems to be fine on barrels ALTHOUGH I've always had my concerns…while the appearance is pleasing to the eye that's my single biggest complaint about the federal trophy bonded tip: the nickel plated bullet makes me nervous about scouring the barrel. I wish it was just a normal copper bullet, or maybe coated with a lubricant but nickel…I dunno Haven't heard any complaints about that though, but also don't know anyone who shoots those bullets by the hundreds to know either way, that's not what they're for.

As for uranium: the issues with using that are immediately obvious and for hunting I'd put money down that it wouldn't be any better a material than lead and copper and would probably be much much worse.

Steel has been and is incorporated, there are copper washed mild steel jacketed bullets out there (com bloc ammo mostly), fmjs with steel penetrator rods, and things like the hornady dgs and dgx bullets, the woodleigh dangerous game fmj round noses, and the old Winchester/Nosler partition gold. It is potential useful BUT only as a means to compliment the primary usefulness of copper and lead bullets it's incorporated into. As a stand alone material it sucks.

Tungsten: well that's been done even in civilian/hunting rounds. Think back to the Barnes MRX. That was an excellent bullet, combining all the pros of lead free monos and eliminating one of the biggest downsides: the fact that they're always much lighter than lead core bullets of similar profile. Had a rear core containing a tungsten alloy much heavier than lead, but it was simply too expensive even for premium bullet buyers in proportion to what it gained. The market spoke. Then there was that gimicky line of ammunition for awhile called "Extreme Shock". Anyone remember those adds in the old hunting and g&a type magazines? A copper jacketed bullet with a core of compressed sintered tungsten. Again, unbelievably expensive AND…underwhelming performance in the real world. A solid tungsten penetrator is a legal problem and for good reason AND…would merely punch a hole through a game animal.

There is nothing new under the sun, as the preacher/teacher/leader of the assembly
in Ecclesiastes says. Every few years there's claims about a novel approach to bullet tips (for what it's worth the first true polymer tipped bullet was the Canadian made CIL "sabre tip" which came out in the late fifties or early sixties, beating Nosler's ballistic tip by DECADES…but of course that was just a less expensive Remington bronze point ) , or yet another "genius" reintroduces a rebated boat tail metal tip bullet with bc's that seem too good to be true…because they are, or yet another iteration of frangible sintered metal core bullets emerges proclaiming to represent a completely new level of terminal efficacy…only to fade into obscurity in due time FOR DUE CAUSE, or a manufacturer of a mono claims to have done the unprecedented with their pressure reducing seating depth insensitive shank geometry…at the end of the day they are all just iterations of grooves, drive bands (whether curvy - oops, I meant "parabolic" ), or conventional, or bore riders, which we've known about for a long time, just changed enough from what came before to get a new patent if need be.

I realize I rabbit trailed away from new materials to new ideas in general: I don't want to come off as being against new developments but really if there's one thing the last 150 years of people innovating and improving bullet technology has shown us it is that lead and copper are the KINGS of bullet making materials, and this proven over and over and it hasnt been because no one has bothered to try to dethrone them.

If it suddenly becomes plentiful and cheap you know what might make an awesome bullet material for terminal and external ballistics: PURE GOLD!

 

[Calvin45]

I can tell you that Bryan Litz knows a 1000 times more than Hammer owners do about ballistics.

i wasn't questioning litz as an authority on external ballistics which he is to me, I was asking if this actually happened that "the hammer people told him he didn't know what he was talking about". Is that a paraphrase or did that really happen? I haven't heard anything about this either way. Sincere question here.

 

[ButterBean]

i wasn't questioning litz as an authority on external ballistics which he is to me, I was asking if this actually happened that "the hammer people told him he didn't know what he was talking about". Is that a paraphrase or did that really happen? I haven't heard anything about this either way

I can assure that They did not, totally BS

 

[JAYgs8163]

I can assure that They did not, totally BS

Where was this information even gathered from by the poster of it here? Not that it really matters just curious.

 

[nralifer]

And the same for you? Or are you on par with Litz

Never meant to imply anything of the sort. You are reading things into that statement. Litz is an engineer by training and has testing equipment we could only dream about. With regard to BCs, a stated BC on any manufacturer's bullet should be taken as an initial starting point. The fact is that each rifle creates its own BC on any specific bullet it fires. If you look at PDM data generated by Litz, that is plainly evident. A PDM is a personalized drag model created by his Doppler radar that tracks the bullet 1500 yds. It can compute a BC for every yard the bullet travels. The G1 and G7 BCs for a specific bullet when fired from different rifles can vary as much as 8% or so. I would be very careful to criticize Litz on anything related to ballistics

Hammer heavily and publicly criticized us for having petals saying that they would be ashamed of showing such a bullet. In fact it was a 150 gr 308 BD bullet I retrieved from a 600 lb Black Bear I shot in Alaska. The Bear took one step and collapsed dead. The bullet had penetrated 30-32 inches though the chest in a diagonal. It was our first generation bullet. No bullet could have performed better. The guide was impressed.

 

[Calvin45]

Where was this information even gathered from by the poster of it here? Not that it really matters just curious.

no no, it does matter! I too would like to know what the heck is being referred to here or if a baseless accusation is being pulled out of thin air. We all know that Litz has worked harder than anyone alive or dead to understand external ballistics and bc values. Nobody in this industry would be stupid enough to actually say he didn't know what he was talking about REGARDING THAT SUBJECT. To claim that a bullet manufacturer said that, therefore, is a big claim and says something very bad about that bullet maker's intelligence.

So, to those who claim "the hammer people" actually said that about Litz….put up or, well, you know

I could totally see a hammer fan saying something stupid, as with any human being. I also know someone who's a real A-hole and drives a Chevy truck…that has nothing to do with the credibility of the CEO of Chevrolet (though I'm sure that's suspect for reasons all it's own)

 

[nralifer]

Lead really is a wonderful material for bullets that you want to expand…it's cheap, plentiful, extremely dense which is always a good thing especially regarding external ballistics as well, and it's soft and malleable. Very hard to beat.

Copper shares some of those virtues, ductile, malleable, definitely harder AND more cohesive, less disintegrating…this can be both a good thing and a bad thing. But the use of copper or gilding metal in bullets was originally about needing bullets that could survive a trip down rifling at the velocities with smokeless propellant, and it proved useful on targets as well, either in full metal jackets that enabled unprecedented penetration at high velocity or soft points that did a lot of damage via the deformation of lead WITH much greater penetration on account of the copper jacket.

There simply isn't a metal in the periodic table that is as cheap and easily workable BUT MORE IMPORTANTLY ultra dense while being soft and readily deformed for terminal efficacy as boring old lead.

And whether in monolithics or jacketed lead bullets, many have indeed tried to find something better than gilding metal or pure copper…and failed. Brass is brittle as all get out in comparison (and still a copper alloy). Aluminum is abrasive as all hell. Nickel is very slippery which is good BUT is also very very hard. Too hard. They found that with Cupro-nickel jacketed bullets back in the day. Nickel plated copper seems to be fine on barrels ALTHOUGH I've always had my concerns…while the appearance is pleasing to the eye that's my single biggest complaint about the federal trophy bonded tip: the nickel plated bullet makes me nervous about scouring the barrel. I wish it was just a normal copper bullet, or maybe coated with a lubricant but nickel…I dunno Haven't heard any complaints about that though, but also don't know anyone who shoots those bullets by the hundreds to know either way, that's not what they're for.

As for uranium: the issues with using that are immediately obvious and for hunting I'd put money down that it wouldn't be any better a material than lead and copper and would probably be much much worse.

Steel has been and is incorporated, there are copper washed mild steel jacketed bullets out there (com bloc ammo mostly), fmjs with steel penetrator rods, and things like the hornady dgs and dgx bullets, the woodleigh dangerous game fmj round noses, and the old Winchester/Nosler partition gold. It is potential useful BUT only as a means to compliment the primary usefulness of copper and lead bullets it's incorporated into. As a stand alone material it sucks.

Tungsten: well that's been done even in civilian/hunting rounds. Think back to the Barnes MRX. That was an excellent bullet, combining all the pros of lead free monos and eliminating one of the biggest downsides: the fact that they're always much lighter than lead core bullets of similar profile. Had a rear core containing a tungsten alloy much heavier than lead, but it was simply too expensive even for premium bullet buyers in proportion to what it gained. The market spoke. Then there was that gimicky line of ammunition for awhile called "Extreme Shock". Anyone remember those adds in the old hunting and g&a type magazines? A copper jacketed bullet with a core of compressed sintered tungsten. Again, unbelievably expensive AND…underwhelming performance in the real world. A solid tungsten penetrator is a legal problem and for good reason AND…would merely punch a hole through a game animal.

There is nothing new under the sun, as the preacher/teacher/leader of the assembly
in Ecclesiastes says. Every few years there's claims about a novel approach to bullet tips (for what it's worth the first true polymer tipped bullet was the Canadian made CIL "sabre tip" which came out in the late fifties or early sixties, beating Nosler's ballistic tip by DECADES…but of course that was just a less expensive Remington bronze point ) , or yet another "genius" reintroduces a rebated boat tail metal tip bullet with bc's that seem too good to be true…because they are, or yet another iteration of frangible sintered metal core bullets emerges proclaiming to represent a completely new level of terminal efficacy…only to fade into obscurity in due time FOR DUE CAUSE, or a manufacturer of a mono claims to have done the unprecedented with their pressure reducing seating depth insensitive shank geometry…at the end of the day they are all just iterations of grooves, drive bands (whether curvy - oops, I meant "parabolic" ), or conventional, or bore riders, which we've known about for a long time, just changed enough from what came before to get a new patent if need be.

I realize I rabbit trailed away from new materials to new ideas in general: I don't want to come off as being against new developments but really if there's one thing the last 150 years of people innovating and improving bullet technology has shown us it is that lead and copper are the KINGS of bullet making materials, and this proven over and over and it hasnt been because no one has bothered to try to dethrone them.

If it suddenly becomes plentiful and cheap you know what might make an awesome bullet material for terminal and external ballistics: PURE GOLD!

Have to hand it to you. You seem to have an encyclopedic grasp of small caliber bullet history. Your post was very interesting to read.

 

[Calvin45]

Have to hand it to you. You seem to have an encyclopedic grasp of small caliber bullet history. Your post was very interesting to read.

I get called a walking encyclopedia by my friend group a fair bit. It's not always a compliment . Just the way my ADHD brain works, I have a tremendous capacity to remember volumes of random bits of mostly useless information but struggle to remember where I left my keys, wallet, when my appointments are, which clothes go in which kid's drawer, what people's birthdays or phone numbers are…thank God I'm married to a wonderful woman who has THAT kind of useful memory