TexasCHLforum.com

baldeagle wrote:

suthdj wrote:There were some links posted somewhere on this site here is one.
http://www.firearmstactical.com/pdf/fbi-hwfe.pdf" onclick="window.open(this.href);return false;

There was another with drawings of wound cavity that was good also. Just can't find it.

Thanks for the link. I'm still reading, but this one statement really struck me. "The impact of the bullet on the body is no more than the recoil of the weapon." If you think about it, that makes sense. Newton's law says that for every action there is an equal and opposite reaction. The recoil you feel will be the same as the impact of the bullet felt by your adversary. If you think about the recoil you feel when you're shooting, that isn't enough to knock you over or even cause you to lose your balance, unless it's a very large caliber weapon and you are unprepared for the recoil.

That is essentially correct, although if you want to get technical some energy is absorbed by the inertia of the weapon itself and the cycling of the slide in a semiauto. The recoil you feel is also spread over your hands, arms, and shoulders whereas the impact of the bullet is concentrated on a small area. However, the impact of most pistol rounds is not nearly enough to physically knock an adult down. If they carried that much energy, the shooter would find himself on his butt as well.

A rough equivalent would be that a torso hit with a .45 slug might feel much like a punch if you were in a frame of mind to notice and make such observations. Some folks who are doing things that make it necessary to shoot them are not, and it's not unusual for them to show no immediate reaction at all while they keep doing whatever it was they were doing just then.

The laws of physics don't have exceptions for bullets.

USMC-COL wrote:

garcia946 wrote:For me it is the stopping power , Ive heard alot stories from alot of friends that are LEO and for them a 9mm just doesnt cut it for them. So they recommend at least a .40 if not a .45 which most LEO carry .45 these days.
But this is ONLY my opinion , no more no less

The largest police department, the NYPD, carries 9mm Glocks with GD 124-gr +p ammo. They are happy with the results. They have no plans to change.

Then again, they carried 158 grain solid point semiwadcutter ammo for many years after everyone else had gone to hollowpoints.

They also refused to consider hollowpoints when they issued the original Glock pistols a number of years ago. The brass was happy with the politically more acceptable FMJ ammo and changed only after taking heavy flak because it regularly overpenetrated bad guy targets that weren't terribly impressed by the rounds' passage and kept taking out civilians and cops on the other side.

The current rabidly anti 2A mayor would never allow NYPD to use any ammo whose caliber started with a 4. That agency's choices have been historically and currently constrained by factors other than optimum performance. This makes the fact that they use the 9mm not necessarily good evidence of superiority over larger rounds. That being said, 9mm Gold Dot is a very fine round, and is probably one of the top 3 or 4 service loadings in that caliber. If you're going to carry a 9mm, it's one of the best choices out there. However, NYPD took a long and circuitous route to arrive at this selection.

Vecco wrote:The Hatcher Formula is an attempt to mathematically evaluate the approximate effectiveness of pistol ammunition at incapacitating a person. Developed by Gen. Julian Hatcher in the 1930's, it uses the bullet momentum, frontal area, velocity, and a 'form factor.'
The formula is:
RSP = M * A * F
where RSP = Relative Stopping Power Index, M = Momentum of the bullet in foot pounds, A = Area of the bullet in square inches, F = Form factor derived from his observations with some additions for later bullet types.

Hatcher Formula
Used to decide stopping power of a pistol in SD, the best stopping power is 50 with anything going over 55 having diminishing return and more recoil

45 = 60.7
40 = 59.4
10 = 62.1
9 = 39.9
380= 18.3

Mass x Velocity = momentum

Momentum = penetration depth.


Quick list of bullet stopping power based on the formula

http://www.abaris.net/info/ballistics/hatcher-table.htm" onclick="window.open(this.href);return false;

The Hatcher formula was a considerable achievement for its day. Those who carry rounds other than the 9mm and .45 may be interested in seeing where those rounds fall on the Hatcher scale. However, that piece of research was far from the last word.

There are many more variables in a real life shooting situation than are accounted for in the formula, and mass and velocity do not address them all. For example, modern hollow point ammunition was not available at that time and ballistic gelatin for accurately gauging relative penetration in a standard medium had not been developed. The formula also does not take into account performance with intervening materials (e.g., glass, light clothing, heavy clothing, leather, wallboard, etc.).

A much more comprehensive look at how all these factors come together in the real world can be found in the FBI's wound ballistics test report prepared in 1989 by SSA John Hall (who I knew personally through my time at the FBI Academy). For those who are seriously interested in gaining detailed knowledge of the issues, the full report can be found here.

The information on specific cartridges is now out of date because there have been major advances in bullet construction since that time, but the test protocols and performance standards are still in use by many law enforcement agencies who are trying to make sure they select, buy, and issue only the best of the best today.

Wound ballistics research is ongoing, and major new information still emerges periodically and past ratings constantly require revision due to advances in ammunition construction. Here's my take on the current state of affairs as they apply to self defense:

1. There is still no magic bullet, and I'm not holding my breath for seeing one in my lifetime

2. Within the same caliber, bullet placement is more important than bullet construction.

3. Any gun is better than no gun if those are your only options, with the caveat that little low energy rounds make little holes. While these wounds may eventually be disabling or even fatal, those effects often occur long after they're of any benefit to the defender. This means that a well placed .22 cannot be relied upon to stop an imminent threat as relaibly as a similarly well placed .45 in a short enough time frame to meet your needs, and that .45 is nowhere close to 100% either.

4. If faced with the options of flinging tiny projectiles from a small caliber handgun or a brick in an arms length life threatening encounter, the real life fact is that in many cases you'd be better served by the brick.

.30calSolution wrote:The caliber and platform thing comes down to personal preference. What is most important is well placed shots.

USA1 wrote:Why carry a .40 or.45

Because they don't make a .46

Well, they do make a .46. I just don't own one.

The old saw needs to be updated to "Because they don't make a .55"

92f-fan wrote:My law enforcement contacts prefer 9mm - their experience in seeing people get shot with various calibers is that fewer people get up from 9mm than from 45.

Maybe due to shot placement - maybe luck - but I dont get shot at for a living, thank goodness and therefore I take the advice of my trusted friends who do. Rather than Internet conjecture

I suspect that observation may be due to the fact that folks shot with 9mm's often don't react right away, so the shooter keeps shooting. The terminal effect is more due to the number of leaking holes in the plumbing than the caliber of the round.

There are no magic bullets, and either caliber can get the job done if it is skillfully used. I put my eggs in the .45 basket because I think it offers a slight edge in some situations, but I wouldn't disparage anybody who chooses to cast his lot in with the 9.