I have read about the 155 grain JHP possessing the balance...

[Captain O]

of penetration and expansion for personal defense purposes.  Bear in mind that expansion is not the be-all-end-all for shocking (not stopping) power.

We're all familiar with the maxim:

"Shot placement is king,
penetration is queen.
Everything else is 'angels dancing in the heads of pins'".

After extensive analyisis, a bit of expansion is needed to avoid overpenetration and some energy deposit. The question remains, what is the proper balance for civilian PD purposes.  We all know that Police use doesn't always correspond directly with civilian applications. Has anyone come across the formula for our applications?

Perspiring minds want to know. 

[Blades]

Perspiring minds want to know. 

Yes we do.

[DM1906]

......We all know that Police use doesn't always correspond directly with civilian applications......

Unless you are referring to tactical deployments, the "application" is the same. Same mission. Same bad guys. A civilian is MUCH less restricted in regards to weapon and ammo choices. Only 2 things matter.... Who's right, and who's left. Use the tools available that will best get the job done. If you know now just exactly what type of situation you will be in when it matters, I'm all ears.

[Blades]

I read an article online somewhere that the 10mm can make a "not-so-good" 155 bullet perform better, I imagine from the extra speed that it gets(if you are using a long enough barrel. A Glock 29 barrel drains some speed from the 10mm.
I saw one post where they stagger the rounds in the magazine. I forget what they started with, but it may have been 155, 180, and 200, then start over. Possibly it could have been 135, 155, 180, 200.
I have been bouncing all over the internet reading about 10mm the last few months I forget where I see what. Mostly what I see is "experts" saying "all you need is 9mm, why carry 10mm, yadda, yadda, yadda." I know there are plenty of threads about ammunition selection, I'll stop rambling.

[DM1906]

The info you're gleaning is primarily speculation based on individual experience (myself included), laboratory test results, and pure guesswork based on what someone read somewhere else on the interwebs. The guesswork is useful as a starting point for actual testing (meeting of the minds, so to speak), while experienced speculation is only slightly better. The lab test results may be VERY useful, if I'm ever in a shootout, in a laboratory. The rest is marketing hype.

[Geeman]

I was attacked by a block of gelatin, and I lived to tell about it... 

For 10mm, I prefer a slightly heavier bullet.  The faster a bullet (JHP), the less it penetrates.  155g is ok, i65g is better and heavier is useful too.

All the efforts we put into deciding SD ammo, and I hope its all wasted time.  I'm in hopes that I'll never need to actually need to touch off a round in a self defense situation.  So far, so good.

I just got to thinking, I carry Underwood Gold Dots in 165g and 180g and if I ever needed to defend myself, I would likely fry the remainder of my already poor hearing, unless the bad guy let me put hearing protection on first.  Perhaps I should choose something with less muzzle pressure....



Greg

[Dave84]

My opinion on the magic bullet grain for 10mm that stays very close to the desired 12" is the 165 grain gold dot from Underwood.

[DM1906]

12" (human target) penetration isn't "desired". It's an absolute minimum. This doesn't take into account any common barriers, where 12" penetration is still the absolute minimum.

[sqlbullet]

And over-penetration is bunk.

Sorry if I am offending anyone.  Most shots fired by police officers miss the target.  Talk about over-penetration.  The over-penetration hype is cooked up by some self-proclaimed guru.

Like DM1906 said.  12" is an absolute minimum.  And a 223 or 308 is preferred.  Know your target and what is beyond.

I will further comment that you should think through fields of fire in your home.  Know where collateral's are and where you can aim to miss them.

[DM1906]

And over-penetration is bunk.

Sorry if I am offending anyone.  Most shots fired by police officers miss the target.  Talk about over-penetration.  The over-penetration hype is cooked up by some self-proclaimed guru.

Like DM1906 said.  12" is an absolute minimum.  And a 223 or 308 is preferred.  Know your target and what is beyond.

I will further comment that you should think through fields of fire in your home.  Know where collateral's are and where you can aim to miss them.

(bold)
No offense taken.

The actual FBI study statistic is 80%. MISS. That's 1 in 5 fired rounds that actually find the intended target. That's for LEO's in actual shootouts. Civilians, actually fare a % or three better. Handgun penetration means NOTHING, when we should be fighting these battles with rifles! Your opposition knows the same thing, and they try. Taking a handgun to a rifle battle is not much different than taking a knife to a gunfight. Your start is already at a gross disadvantage. You may be worried about "over-penetration", but the bad guy isn't. 12-18" penetration may be desired, but is in no way a limitation. This, according to the FBI minimum standard for handgun performance.

[Captain O]

I agree, the "overpenetration" threat is but a myth. By all that's Holy, I want to reach the "vitals" and then some! It is for this very reason that I distrust the .380 Auto.

If you:

a) start with a heavier bullet than the .32 ACP with,

b) the identical case length,

c) the identical bullet velocity (standard US loads).

This will likely yield less penetration, (ask Erich from the Smith and Wesson Forum) he will enumerate the .380's notable lack of penetration, primarily due to the use of hollowpoint bullets.

In fact, he told me of a shooting involving a man (bad guy) that was shot with "hardball" .380 ammunition from the backseat of a full-sized four-door American sedan. The victim (shot at a range of 18"- 24" from the pistol's muzzle) slumped on the vehicle's steering wheel. When the "victim" was pulled from the wheel, the spent FMJ bullet rolled out of the "victim's" mouth! This was just one example Erich cited from the inside the walls of the Albuquerque Coroner's office.

This told me all I need to know about short-barreled .380 ACP pistols. As Erich (an attorney working in conjunction with the Coroner's Office) said regarding hollowpoints in the .380 case... "Why would you put 'speed brakes' on a projectile that leaves the barrel at subsonic velocities"?

This made perfect sense to me.

 

[sqlbullet]

I would clarify that the heavier bullet is a larger diameter.

Or, said differently, sectional density matters in terminal performance.

[Captain O]

I would clarify that the heavier bullet is a larger diameter.

Or, said differently, sectional density matters in terminal performance.

Precisely!