Bullet Construction vs Lethality

[JAYgs8163]

Perhaps, but with the OP's parameters, it complicates things ...

So do Cigar cults.

 

[Northkill]

Do you make copper or lead based bullets or both?

He's lead engineer at Berger

 

[Northkill]

When we began our journey into making bullets, we knew that we wanted to open the nose of the bullet like a banana and shed those petals to achieve a flat front retained shank. Like shooting a flat based bullet backward. Again based on the Rathcoombe physics paper showing this form to create the largest wound channel and longest penetration. In the beginning we gave no thought to the process of shedding weight or what that shed weight did. Animal testing showed us that there was something to the shedding. Several things actually. 1st, there is a shock that happens that moment of opening and shedding. Much greater than a bullet that opens but retains all of it's weight. I'll come back to this. 2nd, without shedding the frontal area of the bullet becomes too large causing it to slow down too rapidly robbing it of its ability to make a large permanent wound channel. Remember vital tissue is elastic and the faster an object goes through it the more permanent disruption it makes. As a bullet slows the wound that it makes becomes smaller until it stops where is no longer makes any wound. Too large a frontal area and a rounded shape lessen the wounding. 3rd, the shed weight increases the stability of the retained shank aiding in longer straight line, meplat forward, penetration. 4th, a flat front retained shank is less likely to deflect off angled bone impacts. Whether it is edge of bone or angled shots. Again, better straight line penetration. 5th, the wounding that happens from the shed pieces as they pass through the animal. Yep, that's right. the shed petals from our bullet often exit the far side around the exit from the retained shank. Radiating at a very slight angle. This greatly increases the total area of the permanent wound channel.

Back to number 1. We control the amount of shed weight based on how deep we make the hollow point. This shed weight will remain the same with high or low velocity impacts. This is due to the raw material that we use, not any kind of scoring or broaching done to the bullet. @nralifer is correct about the brittle coppers breaking and tearing too much. We used that copper in the beginning because we could get it to shed but it is very velocity dependent on how much bullet weight would be retained. Too deep a HP and it would come undone to several pieces at low vel. Too shallow and it would not lose enough weight and would break the nose off into a newly pointed bullet. Not good, but all we could find at the time and other big companies used it. High vel is easy with almost all copper. Back to our copper. If this shedding weight is a good thing, then shedding more is a better thing. Right? Well, that turns out not to be true. There is a dwell time that takes place during the moment that the bullet opens and sheds. If not shedding enough it lessens the shock and the extra wounding done by the shed pieces. If shedding too much, it takes longer for it to happen and too much bullet vel is lost to the process of shedding, lessening the size of the permanent wound channel due to lack of vel and lack of penetration. Over the years we have made some of our hollow points deeper and now in some cases coming nearly full circle to where we started. Not quite, still shedding more than what we started out doing. As a formula guy, this frustrating because there is no formula to it. Depends on nose length, and caliber, along with sectional density and other things. Over time it has become more of a feeling when looking at a new bullet design and determining how much of it to shed to get the most out of it.

Tips are another thing. I swore that Hammer Bullets would never have a tip. The tip is just a plug in the hole that has to be evacuated in order to get fluid into the hollow point to expand the bullet from the inside out. We tried aluminum tips and copper tips. They inhibited low vel performance and would break out to the side, causing irregular deformation and deflecting, along with changing direction of travel. Unpredictable straight line penetration. We had pretty well written off tips. As long range guys we wanted them to work in the worst way but there was no way we could market a bullet that had a lesser terminal performance than our current line of bullets. Consistent terminal performance matters more than anything else. Now we have a line of tipped bullets. Our good buddy @pickens72 came out to visit a bit over a year ago and pushed us to make a tipped bullet. We gave in, mostly to prove to him that it wouldn't work. This time we designed around a particular tip design of poly. Dang if it didn't work. I don't want to give him too much credit, it'll go to his head! So we set out testing on animals for the next year and tweaking as we went. We were personally part of over 100 animal tests and we also got them into the hands of others that shot more animals than we did. Particularly @fordy who set out to make it fail and couldn't. I know he pushed something close 1000 animals in his testing. He can verify the numbers. This design does not deflect like other tipped bullets on angled bone shots and we are actually seeing better terminal results at low to mid range impact velocity. 2800 fps down the wound channel stays the same. Defying common knowledge that the wound will get smaller with less vel. Has to do with tip material, bullet material, and how the two are married together. Again no broaching or scoring of the bullet to encourage deformation, maintaining the proper amount of force and time needed for full deformation and shedding, maximizing the initial shock from deformation and keeping the shed petals on the same straight line penetration of the retained shank.

I am not trying to P in anyone's cheerios. I think @nralifer is making a fine product and he looks at this from a different angle than I do. I do like talking about material and design to reach the end goal of the best possible product. I think we all (in the business) strive to make better. This is just some of the evolution of how we got to this point so far.

Thanks for the story. I like how you give some grace to @nralifer too. Keep up the good spirit.

 

[FEENIX]

So do Cigar cults.

The ones I know only care about their Scotch.

I gave up smoking in 1982. Cancer sucks!

 

[JAYgs8163]

The ones I know only care about their Scotch.

I gave up smoking in 1982. Cancer sucks!

Yup. 5 guys hanging out smoking cigars and drinking scotch always results in solutions!

 

[FEENIX]

Yup. 5 guys hanging out smoking cigars and drinking scotch always results in solutions!

Maybe that is what I am missing. I love my Scotch but without a cigar.

 

[RichCoyle]

FEENIX,

I actually mean to hijack this thread for something important to me. Is your cancer in remission? I know we don't know each other, but I am greatly concerned about it. Hang in there and give your family all the love you can.

Now back to your regularly scheduled thread of shooting and killing poor defenseless creatures.

 

[asd9055]

The ones I know only care about their Scotch.

I gave up smoking in 1982. Cancer sucks!

Gave up smoking in 1987, how ever once every couple of years, I do enjoy a nice Partagas, more if its Havanna. I will NEVER give up my single malt. I am the cult, the scotch cult!

 

[FEENIX]

FEENIX,

I actually mean to hijack this thread for something important to me. Is your cancer in remission? I know we don't know each other, but I am greatly concerned about it. Hang in there and give your family all the love you can.

Now back to your regularly scheduled thread of shooting and killing poor defenseless creatures.

I suppose after 2+ years, I am doing OK per MD Anderson Cancer Center in Houston and Benefis Sletten Cancer Institute in my hometown. I am told the critical period is 2-3 years after surgery. Thanks!

 

[nralifer]

While this is certainly a contentious subject, I enjoy reading these threads. I am the lead engineer at a bullet manufacturer and I have done considerable ballistic gel testing and shot several hundred big game animals personally and seen several hundred more shot by others all over the world. Most at under 400 yards but a dozen or so at long range.

I do not clams to have all the answers. But I am a professional engineer and have spent a lifetime studying this subject, more than 6 decades. So, I know a lot about how various bullets perform and I routinely test our own and continually test our competitors in our ballistics lab. I have shot the majority of the big game I have killed with competitors bullets.

I do know there are three mechanisms that cause loss of mobility and/or death to the game animals we shoot.

Those are mechanical destruction of vital nerves and organs by the bullet itself, destruction of nerves and vital organ tissue by the hydrolic shock wave radiating from the bullets path, and the hydrostatic shock wave radiating through the nerves around the bullets path.

The width of the wound channel is directly related to deceleration. The greater the impact velocity and the shorter distance the deceleration occurs, the greater the diameter of the wound will be. And of course the greater the deceleration the less penetration will be

As others have already mentioned the challenge is to get both a deep and a wide path of destruction, those are opposing objectives.

So the best that can be done is to choose the appropriate bullet construction for the situation you expect to be the most common for your hunting situation and type of game animal you will be hunting.

It's easy to get deep penetration and it's easy to get a wide wound channel, it is very difficult to get both.

Lately I have been studying monolithic bullet designs.

I can tell you the most precise monolithic bullet I have tested in my 300 meter test tunnel to date is the 6.5mm Hammer Hunter but it is not the most precise at 1,000 yards due to its rapid loss of velocity, it is less than 1/4 MOA at 300 meters but will only hit an IPSC target 85.4% of the time from that same 1/4 MOA gun at 1000 yards.

The 125 grain Tipped Hammer Hunter when fired from the same gun and same load looses some precision at 300 meters (.41 MOA) but due to the higher BC gains some precision at 1000 yards raising the hit probability to 91.3%.

Conversely the 125 grain 6.5 mm Cutting Edge Lazer is .52 MOA from the same gun at 300 meters but because of it's higher BC the hit probability rises to 98.1%.

I have yet to test the 125 grain Badlands but will update this when I do.

Many other monolithic bullets I have tested are complete failures for long range applications so I won't mention them.

The main difference I see in terminal effects between the Hammer and Cutting Edge bullets I've tested is directly related to the rate with which deceleration occurs. The Hammer is a rapid deceleration due to the loss of the petals so has a wider wound channel. The Cutting Edge is a more gradual deceleration and produces a slightly narrower but also longer wound channel, both are effective at short and mid range. Long range is another story.

That's how I see things at this point in my study.

Very interesting discussion and is clearly in line with the objectives. I am very familiar with the human internal anatomy and the variations of that anatomy that exist in large vertebrates. I can tell you that there are more similarities than differences. To achieve a rapid kill, there are 3 main mechanisms, sudden an catastrophic hypotension, hypoxia and sudden destruction of the brain. The first two lead to rapid cessation of brain function and loss of consciousness. Unless one shoots the animal in the head, all other shots rely on hypotension or hypoxia. As far as vital nerve damage is concerned the only vital nerve to speak of is the cervical spinal cord which if severely bruised or severed will induce immediate 4 limb paralysis and if high enough on the cord, paralysis of the muscles of respiration (muscles between the ribs and the diaphragm). Hypoxia then is the likely mechanism of death.

That said, examining the wound channel and bullet direction are key in understanding the bullet behavior and the mechanism of death. With our bullets, recovery of the bullet is a bonus since about 80+% of the time they pass through. The paths of the wound channels are in a straight line unless a bone has been struck and deformed the bullet. Gels are used as a model for testing expansion and penetration, but are very uniform in density and quite elastic. This latter property shows amazing hydrostatic cavitation as seen on high speed photography, something that likely occurs to a much lesser degree in an animal due to the much lower elasticity of the connective tissue, fascial layers and pelt. Also passage of bullets through animals is harder on the bullet because of potential bone collision and the varying density of the various tissues.

You mention the CE lazer. It is a very accurate long range bullet, but I have it on good authority that expansion at 950 yards of at least the 400 gr 375 cal bullet on an Audad shot 6 times in the shoulder by this most expert of long range shooters, failed to kill that animal rapidly. He finished it off with his pistol. I, likewise had a similar experience with a Warthog I shot with a Barnes TTSX at 50 yds. Had any of those bullets expanded as intended, one and done would be the result. In the case of the Warthog we would not have had to track this animal for 2-2.5 hr back to it's den and kill it there. Examining the original wound channel the path of the bullet was near the inferior vena cava which would have been severed or ripped open by either hydraulic cavitation or wide wound channel, inducing a rapid internal hemorrhage and rapid hypotension with subsequent cessation of brain function for lack of blood flow.

Gel testing for me has been useful in examining those factors which lead to bullet expansion or not. Consistency of expansion and the lower limit of impact velocity able to induce that expansion, is extremely important. On the very first animal we shot with our original first design, the effect of hydraulic cavitation became very evident. Examining the wound channel revealed the path was straight, hit high on the shoulder and was oblique to the cervical spinal cord, passing just beneath it, but the spine bone itself was intact. The only explanation for the dead right there outcome was a heavy bruising of the spinal cord which immediately stopped nerve signal conduction and induced immediate paralysis of all extremities and respiratory muscles. No major vessel was hit and the diameter of the wound channel was that of a fist. Impact distance was 482 yds.

We have had a few customers shoot Elk beyond 950 to a maximum of 1695 yds with various caliber Bulldozer-2 bullets. All were single shot kills. Consistency of expansion is all important. The gel testing has shown us how the structure of the hollow point and the material of the tip is all important in influencing consistency of expansion and minimum impact velocities to achieve that expansion.

I certainly agree that tips and high BC increase the hit probability at 1000 yds, that is why we went to great pains to maximize the BCs of the hunting bullets, use aluminum tips, cut stress groves in the hollow and drill these holes not to go into the shank.

 

[nralifer]

Xxxx

 

[nralifer]

Yes, CIP, SAAMI and NATO

Do you have any pressure data that shows at what peak pressure you start to get early pressure signs such as heavy bolt lift, ejector marks and primer flattening?

 

[nralifer]

You probably interpret Dr Martin Fackler's findings much better than anyone here. I appreciate his work but there is one problem when using his finding with modern hunting or hollowpoint bullets. His findings were mostly from FMJ bullets since his body of work was based on his experience during the Vietnam War. At least as far as I know.

You are right. Most bullet injuries were likely from FMJ bullets at relativity close range 300 yds or less. However, you can see delayed injuries showing up 24-48 hrs later such as in the intestines and ureters that can be close to the bullet path but not directly injured by a bullet impact. It seems that as the FMJ bullet passes at high speed past these structures there is some hydraulic cavitation done and this bruises the structures causing clotting in the small vessels and capillaries supplying blood. Hypoxia ensues causing death of the involved tissue which eventually perforates.

 

[nralifer]

When we began our journey into making bullets, we knew that we wanted to open the nose of the bullet like a banana and shed those petals to achieve a flat front retained shank. Like shooting a flat based bullet backward. Again based on the Rathcoombe physics paper showing this form to create the largest wound channel and longest penetration. In the beginning we gave no thought to the process of shedding weight or what that shed weight did. Animal testing showed us that there was something to the shedding. Several things actually. 1st, there is a shock that happens that moment of opening and shedding. Much greater than a bullet that opens but retains all of it's weight. I'll come back to this. 2nd, without shedding the frontal area of the bullet becomes too large causing it to slow down too rapidly robbing it of its ability to make a large permanent wound channel. Remember vital tissue is elastic and the faster an object goes through it the more permanent disruption it makes. As a bullet slows the wound that it makes becomes smaller until it stops where is no longer makes any wound. Too large a frontal area and a rounded shape lessen the wounding. 3rd, the shed weight increases the stability of the retained shank aiding in longer straight line, meplat forward, penetration. 4th, a flat front retained shank is less likely to deflect off angled bone impacts. Whether it is edge of bone or angled shots. Again, better straight line penetration. 5th, the wounding that happens from the shed pieces as they pass through the animal. Yep, that's right. the shed petals from our bullet often exit the far side around the exit from the retained shank. Radiating at a very slight angle. This greatly increases the total area of the permanent wound channel.

Back to number 1. We control the amount of shed weight based on how deep we make the hollow point. This shed weight will remain the same with high or low velocity impacts. This is due to the raw material that we use, not any kind of scoring or broaching done to the bullet. @nralifer is correct about the brittle coppers breaking and tearing too much. We used that copper in the beginning because we could get it to shed but it is very velocity dependent on how much bullet weight would be retained. Too deep a HP and it would come undone to several pieces at low vel. Too shallow and it would not lose enough weight and would break the nose off into a newly pointed bullet. Not good, but all we could find at the time and other big companies used it. High vel is easy with almost all copper. Back to our copper. If this shedding weight is a good thing, then shedding more is a better thing. Right? Well, that turns out not to be true. There is a dwell time that takes place during the moment that the bullet opens and sheds. If not shedding enough it lessens the shock and the extra wounding done by the shed pieces. If shedding too much, it takes longer for it to happen and too much bullet vel is lost to the process of shedding, lessening the size of the permanent wound channel due to lack of vel and lack of penetration. Over the years we have made some of our hollow points deeper and now in some cases coming nearly full circle to where we started. Not quite, still shedding more than what we started out doing. As a formula guy, this frustrating because there is no formula to it. Depends on nose length, and caliber, along with sectional density and other things. Over time it has become more of a feeling when looking at a new bullet design and determining how much of it to shed to get the most out of it.

Tips are another thing. I swore that Hammer Bullets would never have a tip. The tip is just a plug in the hole that has to be evacuated in order to get fluid into the hollow point to expand the bullet from the inside out. We tried aluminum tips and copper tips. They inhibited low vel performance and would break out to the side, causing irregular deformation and deflecting, along with changing direction of travel. Unpredictable straight line penetration. We had pretty well written off tips. As long range guys we wanted them to work in the worst way but there was no way we could market a bullet that had a lesser terminal performance than our current line of bullets. Consistent terminal performance matters more than anything else. Now we have a line of tipped bullets. Our good buddy @pickens72 came out to visit a bit over a year ago and pushed us to make a tipped bullet. We gave in, mostly to prove to him that it wouldn't work. This time we designed around a particular tip design of poly. Dang if it didn't work. I don't want to give him too much credit, it'll go to his head! So we set out testing on animals for the next year and tweaking as we went. We were personally part of over 100 animal tests and we also got them into the hands of others that shot more animals than we did. Particularly @fordy who set out to make it fail and couldn't. I know he pushed something close 1000 animals in his testing. He can verify the numbers. This design does not deflect like other tipped bullets on angled bone shots and we are actually seeing better terminal results at low to mid range impact velocity. 2800 fps down the wound channel stays the same. Defying common knowledge that the wound will get smaller with less vel. Has to do with tip material, bullet material, and how the two are married together. Again no broaching or scoring of the bullet to encourage deformation, maintaining the proper amount of force and time needed for full deformation and shedding, maximizing the initial shock from deformation and keeping the shed petals on the same straight line penetration of the retained shank.

I am not trying to P in anyone's cheerios. I think @nralifer is making a fine product and he looks at this from a different angle than I do. I do like talking about material and design to reach the end goal of the best possible product. I think we all (in the business) strive to make better. This is just some of the evolution of how we got to this point so far.