I’ve been reading through the stickies and I have a question. I also did a search and came up with nothing.
Regarding handgun ammunition (specifically SD loads). Is the ft-lbs of energy of a given load relevant anymore? From the stickies, I see a trend that penetration is a more important factor (aside from shot placement), and see no mention of ft-lbs of energy.
…a pistol bullet needs to have some kinetic energy in order to penetrate well inside the living target…the largest part of the energy spent is useful to displace soft tissues away from its path…unfortunately such displacement is not a reliable mechanism of wounding…it depends on the characteristics of the tissues and the stress level on them…so the measurement of the KE spent is not a reliable method to rank which pistol bullet is better for self defence purposes…
All the best
Andrea
Within reason, as long as penetration is met, and relible expansion occurs, I think it is relevant. The agencies reporting higher effectiveness with the 357SIG vs. the 9mm even though they expand and penetrate similary corraborates this. Energy=Temporary Cavity. I view TC as an important mechanism in a psychological stop, which I think most “DRTs” really are, unless the CNS is involved.
The only thing I use ft. lbs. of energy for is to estimate RECOIL…
Over the past 25 years, I don’t recall “ft/lbs of energy” as EVER being a relevant predictor of incapacitation or measurement of wounding effects…
Did I miss something?
The only things I have killed are animals, but cranking up the velocity does tend to make things “deader”. Is this more of a function of larger temp/perm cavity and not muzzle energy?
It seems that, at least in the case of the military over the past 100 years, the worldwide service calibers have ended up in the range between 200 and 350 ft lbs of muzzle energy, give or take one way or the other.
On the low end of the energy scale, expanding light weight bullets have inadequate penetration in the 200 ft lb category. Increase bullet weight and decrease expansion or using a non expanding wadcutter gets the 200ft lb cartridges into the acceptable range of effectiveness.
Going up over 400ft lbs of energy introduces weapon controlability, durability and muzzle blast problems that militaries find unacceptable in a general issue handgun.
You are out backpacking and suddenly a grizzly charges you–do you want to defend yourself with a .220 Swift 40 gr polymer tip bullet at 4200 fps or a .45-70 405 gr JSP at 1475 fps?
In that example, of course the Swift 
I wasn’t specific enough, I was inquiring about increased velocity with the same caliber and in the examples I have the same bullet.
I was speaking from experience of going from a .375 H&H 260 Gr Accubond @~2400fps and a .375 RUM pushing the same bullet @ ~2900 fps. The first destroyed the heart and lodged in the spine of a black bear, the second made the thoracic organs into a Slurpy-like consistency.
Also have seen close to the same increase when going from factory .45/70 loads (1400fps) out of a revolver to a max safe load (~1700fps). Same bullets, 300gr Remington JHP. On whitetail the damage between these two loads is comparable to the bears mentioned above.
The velocity delta would lead me to believe that the massive increases in damage are caused by increased crush cavities, temp and permanent. The reason I asked about the ME is that the old timers swear that they see the innards churned up like that when the rounds stay put inside of the critters and do not make it all the way through.
Energy is a poor indicator of terminal ballistics in living targets, because the collision created when a bullet strikes flesh is inelastic (totally inelastic of the bullet stays in the target without passing through), which means that kinetic energy is not conserved, only momentum is conserved. With energy being dissipated by varying and rather unpredictable mechanisms, it’s not a good metric for comparison.
On a side note, playing with the conservation of momentum equations can help explain why no matter how “bad-ass” one’s chosen caliber is, it’s just not in the physics for it to have any sort of literal “knock down” power against adult humans.
After penetration and expansion (if desired) goals are met, velocity (ergo, energy and Temp Cavity), is the most effective “stopping” mechanism, imho.
As a function of the amount of kinetic energy doing work, the speeding missile results in a permanent cavity, a zone of tissue full of extravasated blood, and a temporary cavity in tissue. In water, it also produces a cavity. The volumes of the various cavities in cubic inches are related to the foot pounds of energy expended by the following formulas:
In tissue:
Permanent cavity-2.547 X 10-3 ft.-lb.
Zone of extravasation-30.105 X 10-3 ft.-lb.
Temporary cavity-66.247 X 10-3 ft.-lb.
http://history.amedd.army.mil/booksdocs/wwii/woundblstcs/chapter2.htm
WS6 seems the original question was regarding handgun SD rounds. Your quote seems to be more about high speed rifle rounds.
Hey, I’m no expert.
Impossible to say, but the section right above it was discussing the .45 and 9mm. The term “missile” would encompass the handgun round, however, as would the inclusion of a table listing velocities down to 250fps.
Simply stating the ft-lbs of a load provides zero indication of what that energy is doing. Arrows have 40-60 ft-lbs, and can kill moose, while a .17 Rem with 900 would not be the optimal choice.
The reason we see increased damage from increasing rifle velocities is because we are generating larger temporary cavities in conjunction with increased bullet fragmentation. Simply increasing temporary cavity (without the fragmentation effect) would not have the same effect unless inelatic organs were involved.
Since handgun bullets (sevice calibers) do not have sufficient velocity to generate substantial tempory cavities, or significant bullet fragmentation (if fragmentation occurs penetration is often insufficient). We really don’t see tremendous increases in effectiveness due to velocity increases. What we do see is subtrantial increases in recoil, recovery times, and weapon wear. Handguns are always a tradeoff between power, and portability. 12"-15" penetration with ~1.5-2 caliber expansion has proven to be the most effective performance measurement for service handgun effectiveness.
Some of the specialty hunting handguns like the big S&W .460 can certainly inflict rifle-like damage, and the increased velocity flattens trajectory, and increases the damage caused by the bullet (again due to temporary cavity with fragmentation).
Interesting…From WS6 posted link:
http://history.amedd.army.mil/booksdocs/wwii/woundblstcs/chapter2.htm
Bone Penetration19
Bone offered a situation similar to that found in skin. Here a minimal velocity of approximately 200 f.p.s. was necessary to effect penetration. Once penetration had been effected, any velocity remaining above the 200 f.p.s. would operate to effect deeper penetration in direct proportion to the square of the velocity and the sectional density of the missile. Penetration and damage to bone was effectively gaged by the amount of energy performing work, essentially proportional to the square of the velocity.
While specific experiments were conducted with beef bone, results are substantiated by other work with human and horse cadavers. Results were essentially the same.
In conjunction with these critical velocities necessary to effect penetration, some consideration should be given to the .45 caliber automatic pistol and its load. From time to time, complaint has been registered that this weapon is not as efficient under all conditions as could be desired in a self-defense weapon. A 234-grain full metal patch bullet is used, and it is launched with a muzzle velocity of 825 feet per second. Following is a tabulation of the kinetic energy available with this bullet at various velocities:
Velocity (f.p.s.):
Kinetic energy (ft.-lb.)
825
383700
254600
187500
130400
83300
47Considering the 125 f.p.s. required to effect skin penetration, it can be seen that the remaining velocity and energy are dropped down to at least 700 f.p.s. and 254 ft.-lb., respectively. The penetration of bone requires another 200 f.p.s. and dropping remaining velocity to 500 f.p.s. and energy to 130 ft.-lb. In addition to these losses, passage through tissue results in some retardation, so remaining velocity and energy will certainly be something less than the figures cited. Furthermore, impact seldom occurs at pointblank ranges, and the initial velocity is certain to be something less than 825 f.p.s. when the bullet hits the skin.
19Grundfest, H.: Penetration of Steel Spheres Into Bone. National Research Council, Division of Medical Sciences Office of Research and Development. Missiles Casualty Report No. 10, 20 July 1945.
From an analysis of these facts and the requirements for penetration of skin and bone, it can be readily appreciated that the .45 caliber bullet is of little value as a wound-producing agent except in the softer tissues and at near ranges. The bullet often fails either to penetrate or to fracture bone and practically never shatters bone in the manner common to the rifle bullet or fragment. The Japanese and German sidearms with muzzle velocities of approximately 1,100 f.p.s. were much more effective as antipersonnel weapons than the .45 caliber weapon. While the same bullet with its characteristics was used in the submachinegun, multiple hits probably compensated for the weaknesses, so apparent in single shots.
Of course, the carbine with its much higher muzzle velocity has largely replaced the .45 automatic pistol and is a more effective antipersonnel weapon than any of the sidearms.
Also, this is assuming you are shooting naked people. Various garments have an impact as well, I am sure. Further yet culling energy and effectiveness from the bullet.
What agencies?
Where can I read the information you have?
https://www.m4carbine.net/member.php?u=7925
Any round can fail, but the 357SIG has a great track record as far as I am concerned. In over 200 shootings with the GDHP at the time David DiFabio (owner of now defunct ammolab.com) stated it, it took no more than 4 hits to put the perp down. Same story with over 100 shootings involving the Federal/Olin loadings.
I understand Todd G has info, I dont doubt him. However I’d like to see links to the articles you’ve read. So David DeFabio says it takes no more than 4 shots to take a perp down? Well the TXDPS shooting I cited took six, and the badguy fought all the way to Lubbock. Of course any round can fail, and sure the .357sig has a good record, but so do slower, heavier 9mms.