Bullet energy is calculated by the following equation:
E = (W x V^2) / 450,400
E = Muzzle Energy in Foot-Pounds
W = Weight of Bullet in Grains
V = Muzzle Velocity in Feet Per Second.
Please notice that velocity (V) is squared in the equation, so an increase in velocity makes a big difference in Muzzle Energy, more-so than the weight of the bullet. This is why 165 grain .40 are about the same Muzzle Energy as 180 grain .40.
CrazyIvan is correct in that a heavier bullet will have more Inertia and thus be harder to stop than a lighter bullet, but the lighter bullet (at the same bore pressure) will have a higher velocity and thus hit with a higher ft.-lb. energy. Again, which is why 165 gr. and 180 gr. have very similar results in ballistics gel, since the 165 gr. is traveling a little faster than the 180 gr.
The best way to decide on whether your preferred round will penetrate is to test it in either water or ballistics gel (water is about 2-to-1, so 24 inches of water is about 12 inches of BG, which is what we want for "optimum penetration". This can be done with 4 1-gallon jugs of water) or to check a place like The Box O' Truth - Ammo Penetration Testing to see if they've already tested a round you use. You can also find ballistic gel tested on the internet for just about any round.
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I'm packing 180 grain Remington Bonded Golden sabers. .40. They are not as fast as a smaller bullet but from my testing, They have just enough penetration(not to much) and they mushroom to an incredible size. And out of 180 grains they retain on average 176-174 grains of their mass.
Also to what JAC said, you can make your own ballistic gel, and it works very well, I recommend everyone do it at least once to see the kind of damage your bullets do.
Also Phone books work very well to show penetration. There is an article in I think American Rifleman about how phone books react much like human tissue.
I've read the factory "manual" and phone checked at 2 gunshops in my area without answering my question.
Will an exclusive diet of +p ammo in my Kimber ProCarry be detrimental to my new (as yet unfired) alloy frame .38 Super.(1911A1 style) It seem the +p ammo is more readily available than the standard round.
This is strictly a range/target weapon. Another forum member stated he cracked the frame on his alloy Colt after using +p over a period of time
Any help will be appreciated.
Doc
Last edited by Doctor Larry K; 11-10-2007 at 05:20 PM.
I cannot feature why someone wants to shoot souped up ammo in a firearm designed for standard loads.Even revolvers will wear with +P ammo and the gain is slight.But if you think it is beneficial,at least put the after market buffers in your pistol.There is nothing you can do for revolvers but suffer the loss in accuracy and pay the damages later.Such as lockup and timing. sam.
I have been searching the web a great deel of late trying to find actual fact based information of hand gun ammunition performance for use in a personal defence application.
The info I found was ammo shot into balistic gelatin with 16oz cloth in front of the BG. So far the only three bullet designs that consitantly gave acceptable performace, in that being a minimum of 12" of pennatration coupled with consistant reliable bullet expansion, not stoped or drasticly reduced by the HP cloging with cloth ( basic accptable FBI bullet performance criteria) were shells loaded with these bullets:
<>Speer Gold dots
<>The NEW not old but NEW Remington BONDED core Golden Sabers
<>Barnes all copper HP/HG bullets.
If you do a search you will be utterly amaised by what is out there on bullet performance.
For those intersted go to: boxotruth.com
This WS is all about bullet performance.
P.S.
I forgot to add one other stand out excellent performing round.
<>Winchesters new "Ranger" ammo It performed as well as any in the above test. I should add the test also thought to include ammo recomendations based on barrel length and what thay foundd its impact on bullet performance to be.
At the risk of coming off sounding "Cooperesque" a 230 GR .45ACP FMJ head shot will always do the trick. A hand gun is your across the average room back-up weapon...With enough practice, you shouldn't really need sights, lights or any fancy bolt on crap to drop the ****head invading your space!
For close range Combat use, when I had the choice, it was the old 1911 .45acp and 230gn FMJ.........double tap will always do the job.
Double taps work best... or better, a Zimbabwe, (two to the chest, one to the head) but a lawyer may eat you for lunch. You could always use the drug-induced craze as a defense, because said perp would not feel the first two to the chest. The head shot would turn him out like a light.
Frankly, anyone threatens my family or home, he's going down, one way or another.
Arsenal: .380, .40, .357 Sig, 5.56mm, .308, .45LC and a .30-06 ... said perp is having a very bad day here... GoldDot or FMJ, not a pretty sight.
Double taps work best... or better, a Zimbabwe, (two to the chest, one to the head) but a lawyer may eat you for lunch.
Lawyer gets the double zimbabwe!
Just Jokin, we never came across any Lawyers in the bush. First choice of course was a smokin 7.62 nato round but the 1911 was a **** fine back-up.
What's the difference between Road-kill Lawyer and road-kill dog?
There's skid marks in front of the dog!
Cor-bon. Period. In 9mm it is a proven manstopper and great penetration. The New DPX stuff from them is good as well. If you are worried about ricochet stuff...Glazer...
The 115gr 9mm should run around $20 for 20, and should give you well over 1300fps and in the neighborhood of 480ft-lbs with 12" (FBI standard testing criteria) penetration...Always used it...Always will. Regardless of caliber.
... witnesses will cite acceleration of the vehicle for the lawyer, breaking hard and swerving to avoid the dog. 
