Selecting 45 ACP defensive ammo

[A-R]

Oh, I wasn't inferring that "stopping power" actually existed, if that's what you meant.

I was simply talking about the bullet slowing down in the target and causing permanent cavity damage in its wake (cutting its way through organs with the expanded jacket). That's "energy transfer". I'm a mechanical engineer (work for Peterbilt atm) graduate, so physics is my strong point.

No, a bullet that weighs .0575 lbs (230gr) is NOT going to "stop" a ~175-200 lb person (that's .02875% relative mass). That's like saying if I run at a standing train, that the train will rebound. The energy will be transferred, the metal on the front of the train will warm up (infinitesimally), but no other physical "hollywood" impact would be seen on the train's part.

What you need to strive for, is for the bullet to come to a complete stop inside the target, serrating as much vital organ and tissue in its wake. Maximum circumferance (and radial surface area) of the projectile will accomplish this.

Wondering if we're simply in a semantic standstill .... I've always understood "energy transfer" to be exactly that - imparting the energy (whatever there is) of one object to the other (I like your man running into an oncoming train analogy). What you seem to be describing as "energy transfer" however, is closer to wound characteristics or wound pattern or some other jargon I've weaned from all the ballistics reports I've read (again, I am merely a moderately-read layman at all this).

* Bullet to complete stop inside target - vital, i agree, but I don't equate this to "energy transfer" so much as expansion and efficiency - the reason it's important is why waste any energy by having it exit the target with energy to spare (although I guess a case could be made physiologically that having both and entrance AND an exit wound would be beneficial to more rapid blood loss? (I dunno - I'm getting over my head) - but more important it seems the longer (both in terms of time and space) it stays inside the body, the more damage it can do - again this seems a separate idea than "energy transfer"

* serrating as much vital organ and tissue in its wake - again, I equate this more to "wound pattern" than "energy transfer" - but we're obviously talking same thing - the size, mass, and every-changing shape of the bullet as it makes its way through flesh - obviously all other factors being equal, something like a Winchester Talon type bullet is going to tear more vital tissue because of its jagged edges and wider overall size than an equal size/weight slug that expands less or not at all but still hits with same force and penetrates to same distance (if this is even physically possible) ... I'm thinking of something like an EFMJ (expanding full metal jacket) round.

So the true "magic bullet" is of course one that penetrates as much or more than needed (the FBI's 12-15 inch standard), retains all mass so as to impart the full benefits of it's initial size on all parts of wound channel (in addition to pre-impact benefits of barrier penetration), and expands drastically to give it the most possible wound channel size and tissue tearing effect - thus the largest potential to inflict lethal damage to vital organs, etc.

sound about right?

Fascinating discussion, BTW

[APynckel]

Oh, I wasn't inferring that "stopping power" actually existed, if that's what you meant.

I was simply talking about the bullet slowing down in the target and causing permanent cavity damage in its wake (cutting its way through organs with the expanded jacket). That's "energy transfer". I'm a mechanical engineer (work for Peterbilt atm) graduate, so physics is my strong point.

No, a bullet that weighs .0575 lbs (230gr) is NOT going to "stop" a ~175-200 lb person (that's .02875% relative mass). That's like saying if I run at a standing train, that the train will rebound. The energy will be transferred, the metal on the front of the train will warm up (infinitesimally), but no other physical "hollywood" impact would be seen on the train's part.

What you need to strive for, is for the bullet to come to a complete stop inside the target, serrating as much vital organ and tissue in its wake. Maximum circumferance (and radial surface area) of the projectile will accomplish this.

Wondering if we're simply in a semantic standstill .... I've always understood "energy transfer" to be exactly that - imparting the energy (whatever there is) of one object to the other (I like your man running into an oncoming train analogy). What you seem to be describing as "energy transfer" however, is closer to wound characteristics or wound pattern or some other jargon I've weaned from all the ballistics reports I've read (again, I am merely a moderately-read layman at all this).

* Bullet to complete stop inside target - vital, i agree, but I don't equate this to "energy transfer" so much as expansion and efficiency - the reason it's important is why waste any energy by having it exit the target with energy to spare (although I guess a case could be made physiologically that having both and entrance AND an exit wound would be beneficial to more rapid blood loss? (I dunno - I'm getting over my head) - but more important it seems the longer (both in terms of time and space) it stays inside the body, the more damage it can do - again this seems a separate idea than "energy transfer"

* serrating as much vital organ and tissue in its wake - again, I equate this more to "wound pattern" than "energy transfer" - but we're obviously talking same thing - the size, mass, and every-changing shape of the bullet as it makes its way through flesh - obviously all other factors being equal, something like a Winchester Talon type bullet is going to tear more vital tissue because of its jagged edges and wider overall size than an equal size/weight slug that expands less or not at all but still hits with same force and penetrates to same distance (if this is even physically possible) ... I'm thinking of something like an EFMJ (expanding full metal jacket) round.

So the true "magic bullet" is of course one that penetrates as much or more than needed (the FBI's 12-15 inch standard), retains all mass so as to impart the full benefits of it's initial size on all parts of wound channel (in addition to pre-impact benefits of barrier penetration), and expands drastically to give it the most possible wound channel size and tissue tearing effect - thus the largest potential to inflict lethal damage to vital organs, etc.

sound about right?

Fascinating discussion, BTW

A bullet will only come to a stop inside a body of mass if it loses all its kinetic energy TO that target. This will be a Newtonian equal and opposite type analogy. The bullet, to come to a stop, must decelerate. The velocity differential between it moving and being static will translate into kinetic energy that must be absorbed by the mass that is slowing it down (law of conservation of energy).

When your car decelerates, it is simply removing kinetic energy and momentum from the mass of the vehicle to the brakes and tires by friction through the brake pads to the rotors which are dissipating the energy through thermal convection.

Wound characteristics are a direct result of the transfer of energy from one body to the other, coupled to the geometries, relative densities of interacting mass, mass, velocities etc. The only reason why a larger cavity is created, is because the bullet slows down. The faster the bullet slows down, doesn't tend to directly influence permanent cavity, rather temporary cavity (shock cavity). The "shock" describes what the bullet feels, a jerk. That jerk when transferred to a fluid medium (flesh) creates a splash. That splash must have enough energy to rip the carbon chains apart that make up our flesh for that cavity to remain permanent.

Compare to an FMJ round that's sleek in profile and is extremely high velocity. It will simply go through flesh w/o much damage.

You want the bullet to retain its mass (through deformation), because a more massive object will carry more kinetic energy. You want it to deform at the same time, so that it can impart all that energy from its mass to the mass of the target, so it's a give and take. The more it deforms, the higher the liklihood you will lose mass.

You've got the right idea, I'm just trying to get your terminology correct.

[The Annoyed Man]

IMHO, "Energy" is just another way of describing penetration...........if the bullet is properly constructed.

[speedsix]

...so if the construction of a 110 gr. .38 Spl JHP round and the speed it enters at produces more jagged edges and tearing/cutting than does a 230 gr. .45 JHP round which doesn't expand enough to tear and cut as much, the .38 is, in that instance, a more effective round...right?

[CC Italian]

I can get 135 grain 10mm to do 1750fps out of my 6inch barrel Glock, that is a little over 900ft lbs. So this means it is better then a 230 45 acp doing 900fps that makes about 400 ftlbs,right? Wrong!! Light weight rounds for caliber are for flash and noise imo. Taylor knockdown is a joke! That’s why I shoot them, fireballs are fun . They are fun to blow up water jugs with but I would never carry that round!! Energy is useless unless the bullet penetrates!

Don't try to over think it. Penetrate, expand, and then worry about all the ballistic energy if you want. There is an old FBI write up that talks about the 10mm (can't remember where to find it) but it basically asks the question why not just adopt the .45acp round when it does the same thing a 10mm does to a human assailant with less recoil. I think the projected stopping power if you will call it that was supposed to be within 2% of each other. A lot of the so called short comings of the 9mm have been taken away with the modern hollowpoint loads. Even the newer 9mm hp rounds have a great record! After a certain point it seems to be the law of diminishing return when getting into "stopping power".

[A-R]

...so if the construction of a 110 gr. .38 Spl JHP round and the speed it enters at produces more jagged edges and tearing/cutting than does a 230 gr. .45 JHP round which doesn't expand enough to tear and cut as much, the .38 is, in that instance, a more effective round...right?

IF (big IF) the penetration distance is same for both and IF (another big IF) the two bullets are same relative size/mass/weight to begin with then yes the more jagged edges will prove more beneficial, I believe.

But a full expanded .38 bullet at say 50% larger than original size (0.358 original --> 0.537) is not that much bigger than a non-expanded .45 round so they are likely cutting out the same relative size permanent wound cavity (different from the temporary wound cavity caused by the "shock" etc that gets way over my head ... of course in the manner of its expansion there is tumbling and the jagged edges etc that I assume benefit some over a perfectly smooth FMJ

but you sorta start to see the benefit of a bigger bullet here - a smaller diameter bullet MUST expand well AND penetrate well to equal the results of a larger and deeper penetrating non-expanding bullet (I think - but then all the talk of energy and shock and temporary wound cavity start to confuse me again).

I look at it simply like this - compare a .38/9mm size bullet to a .45 size bullet.

If neither expands at all, and both penetrate same distance - .45 would obviously be better because it made a bigger hole or "wound cavity"
If neither expands at all, but 9mm penetrates deeper - then 9mm MIGHT be better because it MIGHT have hit something more vital (like a heart) that .45 missed
If 9mm expands to relative size of .45 and .45 does not expand and both penetrate same, then likely relatively same result ...
...

anyway you could go on and on with the what ifs

[A-R]

BTW, AndyC and APnyckel ....

your combined understanding of this stuff vastly exceeds my capacity but I'm enjoying reading what both of you have to say as I struggle to explain it all in my own way

[APynckel]

BTW, AndyC and APnyckel ....

your combined understanding of this stuff vastly exceeds my capacity but I'm enjoying reading what both of you have to say as I struggle to explain it all in my own way

If there's anything you need clarification on, I'll do my best to explain it. I know this physics stuff can be tough to grasp. Hell, I sucked at physics in high school, yet somehow gravitated (snicker) towards it and became an engineer.

[A-R]

BTW, AndyC and APnyckel ....

your combined understanding of this stuff vastly exceeds my capacity but I'm enjoying reading what both of you have to say as I struggle to explain it all in my own way

If there's anything you need clarification on, I'll do my best to explain it. I know this physics stuff can be tough to grasp. heck, I sucked at physics in high school, yet somehow gravitated (snicker) towards it and became an engineer.

ok well maybe if you have time at some point you could take the train of thought I started with speedsix above and expand on it with all the variables (penetration, expansion, permanent wound cavity, energy transfer, shock, temporary wound cavity, others?) and maybe we can work up a list of variables that shows the good and bad possibilities of each size/speed of bullet?

Just theoretically of course, for fun

For instance ...

9mm+P 124 grain at 1200 fps = 400 fp energy (rough estimates - i believe this is close to Speer Gold Dot)
45ACP 230 grain at 875 fps = 400 fp energy (rough estimates - i believe this is close to Speer Gold Dot)

now variables:
1. assume both penetrate 12-15 inches, both expand 50% - 45 is better because it's bigger and all other factors are relatively equal, right?
2. 9mm penetrates 12 inches xpands 50% -45acp penetrates 15 inches expands 20% ... which is better?
3. 9mm penetrates 12 inches, expands 50% - 45 acp penetrates 12 inches and expands only 20% ... which is better?
.... and so on

This seems to be the real "proof" in theory is comparing the results of different variables and then trying to determine the likelihood of those variables. But I don't even understand all the factors well enough to make those assumptions of "likelihood" - for instance does the lighter/faster 9mm have a better or worse chance of achieving full expansion than the heavier/slower 45acp? does the lighter/faster 9mm have better or worse chance of achieving full penetration than heavier/slower 45acp? How do those chances change with changes in target construction (meaning if you hit a barrier first, if you hit heavy fabric first, if you hit bone once you're a few inches into penetration, etc)

The one thing I do know (or at least think i know) if neither bullet is expanding at all - i'd rather have the bigger bullet to begin with. Beyond that, I get confused quickly.

[APynckel]

ok well maybe if you have time at some point you could take the train of thought I started with speedsix above and expand on it with all the variables (penetration, expansion, permanent wound cavity, energy transfer, shock, temporary wound cavity, others?) and maybe we can work up a list of variables that shows the good and bad possibilities of each size/speed of bullet?

Just theoretically of course, for fun

For instance ...

9mm+P 124 grain at 1200 fps = 400 fp energy (rough estimates - i believe this is close to Speer Gold Dot)
45ACP 230 grain at 875 fps = 400 fp energy (rough estimates - i believe this is close to Speer Gold Dot)

now variables:
1. assume both penetrate 12-15 inches, both expand 50% - 45 is better because it's bigger and all other factors are relatively equal, right?
2. 9mm penetrates 12 inches xpands 50% -45acp penetrates 15 inches expands 20% ... which is better?
3. 9mm penetrates 12 inches, expands 50% - 45 acp penetrates 12 inches and expands only 20% ... which is better?
.... and so on

This seems to be the real "proof" in theory is comparing the results of different variables and then trying to determine the likelihood of those variables. But I don't even understand all the factors well enough to make those assumptions of "likelihood" - for instance does the lighter/faster 9mm have a better or worse chance of achieving full expansion than the heavier/slower 45acp? does the lighter/faster 9mm have better or worse chance of achieving full penetration than heavier/slower 45acp? How do those chances change with changes in target construction (meaning if you hit a barrier first, if you hit heavy fabric first, if you hit bone once you're a few inches into penetration, etc)

The one thing I do know (or at least think i know) if neither bullet is expanding at all - i'd rather have the bigger bullet to begin with. Beyond that, I get confused quickly.

A handy tool.

http://www.firearmexpertwitness.com/cus ... lcnrg.html" onclick="window.open(this.href);return false;

Honestly, it would be a lot easier than trying to rough out a multi non-linear variable equation to try to simulate terminal ballistics to just mold some ballistics gelatin, and rent a super slow mo camera, and just test each bullet with multiple iterations.

[A-R]

A handy tool.

http://www.firearmexpertwitness.com/cus ... lcnrg.html" onclick="window.open(this.href);return false;

Honestly, it would be a lot easier than trying to rough out a multi non-linear variable equation to try to simulate terminal ballistics to just mold some ballistics gelatin, and rent a super slow mo camera, and just test each bullet with multiple iterations.

Agreed - I was just trying to toy with it for the theoretical fun of it - but proof is certainly in the pudding (er, I mean the gelatin).

I wonder if any of those gelatin junkies has done some research on failure rates - like does a 9mm fail to either expand or penetrate acceptably more of than a 45 or something like that? That might be instructive. I know I've seen that with particular bullet designs and failure rates to penetrate barriers and clothing, but what about to make it through bone or cartilage and still reach the organs? Is slower/heavier better or faster/lighter? And how in the world do you replicate such tests?

But in a nutshell, the main factor is still the bullet's ability to do significant damage to vital parts of the body, right? All we're really discussing is the likelihood of each bullet to do that based on its performance in penetration, expansion, wound cavity, etc .... so based on that perhaps a set of variables that say (and I think this is what FBI determined) penetration is king, expansion is important, shock is nice but not essential? something like that

I mean look at the 5.7mm FN round ... as long as you aim well and it penetrates to the heart (which it seems likely to do) and doesn't disintegrate before it gets there it seems likely to stop a fight rather quickly (especially if the bad guy is behind barriers) - but is it more likely that all those factors will be met - good placement, holds up until hits heart - or even needed (barrier penetration) vs. the more well established characteristics of a .40 or .45 tearing a big hole in someone and causing enough blunt damage to take someone out of the fight?

Feels like high school math/science all over again - I THINK I got it, but then I don't

[MoJo]

Testing in gelatin, wet phone books or newsprint, a water column, sand etc. Just tells us what that bullet will do in that medium. It's important data but, face it, people and animals are not homogeneous mixtures we have fat, muscle, bone, and even relatively hollow spaces in our bodies. All this skews any data we may collect from test media.

Don't get me wrong, the bullets have to be tested in some non living media to assure they will work. But when the bullet hits the flesh all tests go out the window. How many deer have been shot in a vital organ and they still ran for a quarter mile before collapsing? How many humans have been shot center mass and they still fought on? The test medium can not replicate the will to survive, escape or to continue the fight. Arguing over energy transfer, stopping power, knockdown power, high velocity vs. low velocity heavy bullet vs. light bullet makes for some interesting locker room chatter. Real world results on real game or real bad guys tells us a lot more than a "wound channel" in gelatin ever can.

Study actual shooting results when you can get them. Read Marshall and Sanows books on "stopping power" and keep an open mind when selecting the next "wunder bullet." Some aren't as good as the advertisements and gel tests tell us and others are much better than the guys in the lab coats think they will be.

[gigag04]

I use Corbon 185 grain +P in my 3" Kimber and my CW45. Although I have nothing against +P 230 ammo in a larger gun, I'm not confident that there is enough barrel length on a shorter gun to take full advantage of accellerating a 230 grain bullet to +P velocities. In fact, I would argue that shorter barrels make +P necessary with lighter bullets in order to generate enough velocity for good penetration at the given bullet weight. I use standard pressure 230 grain ammo in my 5" 1911 and full sized M&P45 because I think that is sufficient (and because that's what I have on hand); but I keep all of our short barreled pistols loaded with +P, regardless of caliber, and my snubbie is stoked with .357 magnum instead of .38 +P on the same principle.

Teddy Jacobson agrees with you about 3" being too short for .230s, (even .200s really), per a first hand conversation I had with him about the issue. This is solid advice.