Bullet Construction vs Lethality

[nralifer]

I have no problem with a quartering away shot. Very lethal when you can slip a bullet behind the facing shoulder. I was commenting on the original comment in this thread, " any angle"

I shot my Coastal Black Bear at about a 25 degree angle as he was walking away in tall grass. Not an ideal shot for sure, but I knew the bully likely would reach the heart or sever one or both pulmonary arteries. As it turned out the pulmonary arteries were hit because as he went down I could see blood streaming from his nose.

 

[xsn10s]

So if I read correctly the 168 CC has a reported BC of 0.462, and the ELDM of 0.523?

Yet it looks like from limited data, more BC did not pay off here?

I don't remember the BC off hand. I do remember that the ELDM required less dope. The ELDM's weren't coldbore first round hits. Neither were the 168 CC's due to a wind change right when I pulled the trigger. I was on a hilltop and the bottle was about 8 degrees below me between two hilltops. So the wind was a bit more amplified than I thought. I didn't have a spotter so I had to use my reticle (SWFA 10X Milquad) to adjust. Hit the bottle on third shot with 168 CC's and second shot with 168 ELDM's. BC's definitely paid off. I compare shooting low bc high velocity to this like shooting a 22-250 40 gr to this. Yeah the 22-250 is fine out to 400 yards but then is like shooting a rock. And there isn't anything special about shooting a bullet over 4000 fps. I learned this decades ago. This concept isn't new, been around probably what almost nine decades? I'll take higher bc's any day.

 

[nralifer]

Y'all haven't covered it all yet?
very thorough you are!

Actually, what we haven't discussed is the effect of a tip on expansion. I have seen more than once that other manufacturers promote tips as aiding expansion. Their theory is thst the tip pushes back to aid in hollow point expansion. I'm not at all convinced of that. Barnes, Hornady, and Nosler all make formed all copper bullets with plastic tips. Plastic will shatter on impact, so it is hard to envision a plastic tip aiding in expansion of a hollow point. Our bullets contain aluminum tips which in gel testing, are ejected from the hollow within 1-4" after impact depending upon the impact speed. The lower the impact speed, the longer it takes for the tip to be ejected, delaying the onset of ejection. Removal of the tip will significantly reduce the impact velocity at which the bullet will expand. See photos below. At least in Barnes bullets, their tips shatter on impact. We have seen that occasionally the tip stem will not be cleared from the hollow and obstructs the entering of tissue into the hollow preventing expansion. Thus, our data indicates tips delay the onset of expansion. Aluminum is an excellent tip material in that it will not soften or melt during flight, and the shaft bends rather the breaks, facilitating its ejection from the hollow. See photo #4. Photo #5 simply shows the velocity better of the bullet in photo #3.

 

[xsn10s]

The badger was a coldbore first round hit. 260 AI 145 MB at 659 yards. around 4 mph winds. The chuck was also coldbore first round hit at 533 yards I think. I used G7 .340 for my bc. The low bc and high velocity concept (22-250 40gr going 4k fps or better) would have missed both of these shots. I know because the 260 AI was a 22-250 that I used for a decade until the barrel burned out. Might have been able to walk shots in if the badger or chuck was dumb enough to stick around.

 

[nralifer]

The badger was a coldbore first round hit. 260 AI 145 MB at 659 yards. around 4 mph winds. The chuck was also coldbore first round hit at 533 yards I think. I used G7 .340 for my bc. The low bc and high velocity concept (22-250 40gr going 4k fps or better) would have missed both of these shots. I know because the 260 AI was a 22-250 that I used for a decade until the barrel burned out. Might have been able to walk shots in if the badger or chuck was dumb enough to stick around.
View attachment 493851View attachment 493852

 

[nralifer]

We certainly agree that BC is very important.

 

[asd9055]

I was hoping would get around to lethality. We have approached our bullet design from a different persoective. I am a surgeon by training specializing in urology. During my first 2 years of residency I spent at least half at a level 1 trauma center, SF General Hospital, and got to see a wide variety of penetrating and blunt trauma. The most lethal wounds were either penetrating trauma to the vena cava or blunt trauma to the heart. The mechanism of death was always severe low blood pressure either because the bleeding could not be contained, as in the case of vena cava tears or pump failure from severe bruising of the heart muscle as in the case of blunt injury to the heart, hitting the steering column in an auto accident for example. In hunting big game, a catastrophic drop in blood pressure causes rapid unconsciousness because of lack of brain perfusion. An expanding bullet hitting the top of the heart will take out both the main pulmonary artery and aorta causing an immediate catastrophic hemorrhage with resultant immediate and profound drop in blood pressure with cessation of brain activity. The animal is dead right there. Shots through the mid to rear chest are fatal eventually but are not likely to lead to catastrophic blood loss. If both entrance and exit holes are small, what happens is that as the animal inhales, air leaks out into the space called the pleural cavity, causing a gradual buildup of air pressure around the injured lungs that collapses them under pressure causing all blood flow through the lungs to stop, C causing a drop in heart output and blood pressure to the point that the brain stops working and the animal collapses. If the exit hole is large then air pressure does not build up in the pleural space and prevents the complete collapse of the lungs without a rapid drop in blood pressure. The animal can run a considerable distance and die later from exhaustion, infection, or predation, Copper, being considerably harder than lead, will not deform unless the front of the bullet is weakened by a hole. Expansion of the bullet is poor unless there are groves cut into the wall of the hole which act as stressors and allow the copper to tear along those groves, causing the petals to be formed and rolled back. Since the bullet is also spinning about it's longitudinal axis at over 200,000 RPM, these petals act like propeller blades and assist the bullet in penetration. The high forward velocity of the expanded bullet causes a large temporary wound cavity behind the bullet. Non-expanding FMJ bullets just pencil through causing much less tissue damage and much smaller temporary wound cavities. Weight retention is high which adds to the momentum of the bullet, thus adding penetration. The expanded front end also contributes to a straighter path and prevents tumbling. Expansion is around 1.5 calibers. The high BC of our bullets extends the range before minimum expansion velocity is reached. At very high impact velocity, at least in gel, the petals can shear off usually within 10-12 inches snd subsequent tumbling of the shank. No expansion scheme can compensate for a poorly placed shot however.
Photos are of various bullets showing the type of expansion they have in 10% gel.

Thank you! Nice write up
I don't have to use leadfree, so I have not ever hunted with them. I do enjoy learning and this has been educational.

 

[xsn10s]

I was hoping would get around to lethality. We have approached our bullet design from a different persoective. I am a surgeon by training specializing in urology. During my first 2 years of residency I spent at least half at a level 1 trauma center, SF General Hospital, and got to see a wide variety of penetrating and blunt trauma. The most lethal wounds were either penetrating trauma to the vena cava or blunt trauma to the heart. The mechanism of death was always severe low blood pressure either because the bleeding could not be contained, as in the case of vena cava tears or pump failure from severe bruising of the heart muscle as in the case of blunt injury to the heart, hitting the steering column in an auto accident for example. In hunting big game, a catastrophic drop in blood pressure causes rapid unconsciousness because of lack of brain perfusion. An expanding bullet hitting the top of the heart will take out both the main pulmonary artery and aorta causing an immediate catastrophic hemorrhage with resultant immediate and profound drop in blood pressure with cessation of brain activity. The animal is dead right there. Shots through the mid to rear chest are fatal eventually but are not likely to lead to catastrophic blood loss. If both entrance and exit holes are small, what happens is that as the animal inhales, air leaks out into the space called the pleural cavity, causing a gradual buildup of air pressure around the injured lungs that collapses them under pressure causing all blood flow through the lungs to stop, C causing a drop in heart output and blood pressure to the point that the brain stops working and the animal collapses. If the exit hole is large then air pressure does not build up in the pleural space and prevents the complete collapse of the lungs without a rapid drop in blood pressure. The animal can run a considerable distance and die later from exhaustion, infection, or predation, Copper, being considerably harder than lead, will not deform unless the front of the bullet is weakened by a hole. Expansion of the bullet is poor unless there are groves cut into the wall of the hole which act as stressors and allow the copper to tear along those groves, causing the petals to be formed and rolled back. Since the bullet is also spinning about it's longitudinal axis at over 200,000 RPM, these petals act like propeller blades and assist the bullet in penetration. The high forward velocity of the expanded bullet causes a large temporary wound cavity behind the bullet. Non-expanding FMJ bullets just pencil through causing much less tissue damage and much smaller temporary wound cavities. Weight retention is high which adds to the momentum of the bullet, thus adding penetration. The expanded front end also contributes to a straighter path and prevents tumbling. Expansion is around 1.5 calibers. The high BC of our bullets extends the range before minimum expansion velocity is reached. At very high impact velocity, at least in gel, the petals can shear off usually within 10-12 inches snd subsequent tumbling of the shank. No expansion scheme can compensate for a poorly placed shot however.
Photos are of various bullets showing the type of expansion they have in 10% gel.

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.

 

[ButterBean]

@nralifer A good post! I respectfully disagree a little, but appreciate your position.

X-2

 

[Stokesrjsr]

Do you have a ballistics lab to measure chamber pressures?

Yes, CIP, SAAMI and NATO

 

[xsn10s]

Yes, CIP, SAAMI and NATO

I misread your original post on which caliber bullets you were testing. What cartridge are you using? I'll be interested in more of your rate of deceleration testings.

 

[Northkill]

Berger got the equipment for sure. Dream job you got, @Stokesrjsr. I appreciate the ability to be fair and open with the testing results. Looking forward to more.

 

[2buffalo]

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.

Nice to see someone with what appears to be real test data and not a bunch of keyboard warriors using programs to form an opinion about bullets that they have not used or killed game with.

When you are talking about deceleration and effectiveness can you define short, mid, and long range?

 

[A/1-61]

I shot my Coastal Black Bear at about a 25 degree angle as he was walking away in tall grass. Not an ideal shot for sure, but I knew the bully likely would reach the heart or sever one or both pulmonary arteries. As it turned out the pulmonary arteries were hit because as he went down I could see blood streaming from his nose.

That's the most lethal shot on a heavy bear, staying clear of that heavy shoulder bone. I shot a 425 ponder in '82 in the Bob Marshall with that same angle. Road in horseback 35 miles past Shaffer Meadows and camped on Dolly Varden Creek. 450 yard shot from our perch on the Argosy Rim. Got a hard copy photo somewhere. Way before smart phones, back when nobody knew where you were if you didn't want them to.