ballistics

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i couldnt find a post about this so i hope its not a repeat. I am confused about one thing concerning ballistics...whats it all mean? there are hours of numbers to look at concerning ballistics, but i am not aware of any standard to judge by. For instance, i look at numbers associated with muzzle velocity and energy, and i think well this number is higher so it must be better. Then i read about over penetration alot. I guess what i'm asking is, whats the highest number we should obtain for self defense ammo? for that matter, is the highest number really what we are after?
 
Ya, it does get confusing, even more so when people start creating this things like "knock down index" and "one-shot-stopping power"

Here is my thinking on it, since my primary gun is 9mm I look at the 9mm round. I think if a round penetrate to about 14" in bare ordinance gelatin (no denim, no dry wall etc...) and it expand to about .60 caliber - it probably is going to be an effective round. That doesn't mean I can shoot a bad guy in thumb and have it spin him around, send him flying backwards and put him down. It means to me, that if I shoot center of mass the bullets are going to damage and distrupt vital tissue, which in turn should quickly stop the aggression.

When I stand with my back to wall and put a ruler just at chest level - I measure about 12" from front to back. But that doesn't mean that if I'm shot, a bullet that goes 14" in bare ordinance gelatin is going to zip through me and kill someone standing behind me.

The ordinance gelatin tests don't predict exactly what a bullet is going to do in any siven shooting. What the gelatin tests provide is a consistent base line data set to build a correlation from.

So you can say - for example that if bullet such and such penetrates 14.2 inches and expands to .59 caliber in the denim gelatin test, - statistically it will be an effective round. Effective to me means that if I shoot center of mass the bullets are going to damage and distrupt vital tissue, which in turn will quickly stop the aggression.
 
It does get confusing. If your concerned with self defense then you want a bullet/caliber that will penetrate far enough and expand as much as possible. Don't get caught up in velocity and energy to much, your better off checking out articles about proven bullets and calibers. A good example of this is the 357 magnum. The 125 grain bullet is a great man stopper, but poor for deer sized game, (100lb - 200lb game.) Why??? There are a number of factors. The 158 and up bullets are slower but have more ft. lbs and penetrate better on game animals. A 32 H&R mag is faster then a 45 acp but the 45 acp at 800 fps is one of the best calibers out there for self defense.

Check out the Winchester web site for comparison;
http://www.winchester.com/SiteCollectionDocuments/flash-SWFs/law_bullit.swf

The 357 sig is faster then the 147 grain 9mm but the results are close if not in favor of the 9mm on gelatin test. The 380acp has great expansion but the penetration isn't up to the FBI standards, (12 inches or more.)

Different calibers do things differently. A 308 Winchester 180 grain bullet at 2800fps can be used for Moose hunting, but so can a 45/70 405 grain at 1800fps.
 
Here is why I don't chase my tail on trying to figure out velocity and foot-pounds of energy.

If you go to Winchester's site and look at the 40 cal "T" series 180gr - RA430T, you have a 180gr projectile traveling at 990 feet per second. In bare gelatin it penetrates 13.8" and expands to .6"

If you look at the 9mm "T" series 147gr - RA9T, you have a 147gr projectile traveling at 990 feet per second. In bare gelatin it penetrates 13.9" and expands to .65"

http://www.winchester.com/SiteCollectionDocuments/flash-SWFs/law_bullit.swf

In terms of what these two rounds do to the human body - they're virtually identical.

There are other examples of this if you pour through ballistics tests.
 
SD ammo- If it always goes bang when I want it to, and always hits where I want it to, knocks a decent hole in it, I'm happy!:)
 
ballistics isnt the end all ofendalls it claims to be.

in order to make a new product seem worth the price the advertising arm of a company gets out ballistic data, and well tweaks things so that numbers look good.

what do you think is more powerful, 44 special or 44 magnum. on the most basic level 44 magnum is, because it has far more power in the top end of the loading spectrum then 44 special.


the problem here is that only in very limited stages does the 44 magnum actually outperfom the 44 special in the real world.

since ive been trying to get into handgun hunting, a 200 grain bullet moving at 1000 fps is considered the ideal way to go. that applies for any cartridge. so is a 44 mag load pushing a 200 grain bullet at 1000 fps more powerful then the same bullet and velocity in a 44 special case?
 
I guess what i'm asking is, whats the highest number we should obtain for self defense ammo? for that matter, is the highest number really what we are after?
Click to expand...
Short obvious answer is the largest gun that you can afford and shoot well. If you are a 44 magnum guy and can hit a running chicken at 200 yards you have your gun. If you can just hold 8 out of 10 rounds on a silhouette with a 9MM at 7 yards that is your gun. Like the man says do not over think it. Goes bang, hits what you are shooting at, and the good guy goes home in one piece.
 
How fast is it? How heavy is it? How aerodynamic is it?

That's pretty much all there is to ballistics. Everything is Newtonian and google has the answers.

Add penetration and expansion for the self defense part and Bob's your uncle.
 
For SD, the really important factor is reliability. All the velocity, energy, penetration and expansion figures in the world are no good if the round won't feed or the gun won't fire.

Jim
 
OK, so we talk about reliability. But I don't go out and buy a box of every brand of ammo and then run reliability tests on and then go look at the ballistics data on whatever brands made the grade.

I go do research and come up with maybe a top 5 or 6 rounds then I go out and maybe buy a box of the top 3.

If I am getting failures with anything - it gets crossed off the list. I hope no one is going to try to carry ammo in their pistol that stovepipes or doesn't reliably feed - just because they think it's a great one-shot-stopper. That's obviously not a good trade-off.

But on the other hand, my HK P7M8 never failed with any type of ammo period. So the reliability factor of ammo selection was moot.

There are some pisols that are finicky about ammo though. The Rohrbaugh R9 is one of them. Well first of all - it's not recomended that you fire +P ammo through it at all so that narrows your ammo selection for this weapon. But people have reported having problems with different types of ammo. But usually they keep testing stuff until they find something the gun likes. With the Rohrbaugh for instance - it's often 124 Speer Gold Dots. But most people have reported that once they've found the ammo the gun likes - it's very reliable with THAT ammo.

Other pistols can be like that... if you are having problems with a particular type of ammo you have to ditch it in terms of loading it for SD - no matter how good it's test data is.
 
(for hunting) a 200 grain bullet moving at 1000 fps is considered the ideal
Click to expand...

For taking down people, 155 and 158 grain bullets at 1200 to 1250 fps in .40 and .357 caliber seem to be optimum rounds in commonly available ammunition.
 
Secret agent man check out the link I posted and compare the 357 Sig 125 grain T series to the 9mm 147 grain T series and you'll see what I'm talking about.
 
The Winchester chart makes a compelling argument for 147 grain 9mm v 357 SIG, Noreaster, but unaccounted for is the stopping factor from the 357 SIG's much higher velocity. Penetration is not the whole story. The increase in impact force and resulting tissue disruption and damage is what makes them stop and give it up. While it is true a 147 grain bullet at 995 fps may penetrate sufficiently enough to kill, that is not the objective in self defense.

And then there is the feeding issue. A 357 SIG pistol is virtually guaranteed to feed the bottle neck cartridge. I don't think that can be said for any 9mm round, or any semi auto round, for that matter.

These two criteria, stopping capacity and feeding ability, were two major concerns of the Texas DPS when it gave up the 45 ACP for the 357 SIG.

A third major issue was windshield penetration, and there the 147 grain 9mm comes up way short by comparison.
 
Rock Sheriff's up here just had a failure with Gold Dot 357 Sig breaking apart after going through a windshield. The suspect had damage to one eye but is fine going to stand trial for attempting to run down the deputy.
 
There are a couple basic things to consider, the grain weight of the round and how fast it is moving. The higher the grain weight means there is more mass and the faster it goes means there is more kinetic energy impacting the target. The hotter the load means it will do more damage, but the down side is there is usually more recoil to manage. Other things to consider for defensive ammo is expansion and weight retention.
 
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