Self Defense Ammo for CM9

[Thunder71]

Yes, there is... length and overall shape of the bullet itself varies a lot more than I would have thought.

Even with ball ammo there's a big difference.

Federal on left - Remington on right

[Mr. S]

Michael,

Sorry I wasn't very articulate last time.

The major point of my post is that velocity and/or velocity % decrease, in and of themselves are not as important as other factors. You can't ignore them to be sure, but momentum and energy that the bullet transfers to the target can be more significant. A light bullet can make up for the lack of weight by going faster. Conversely a slow bullet can make up for the lack of speed by being heavier. In the table you quoted I was just observing that the faster lighter 124 gr. bullets did indeed lose more speed, but even with that loss were still traveling much faster than the 147 gr. bullets ever did.

Separate from my comments above are the issues of: bullet expansion, weight retention (i.e. you don't want fragments breaking off), over or under penetration, reliability of expansion, reliability of feeding in your gun, what sorts of barriers do you expect to encounter, cost & availability, ergonomics, and many other factors. Indeed these complex and often inter-related factors are why it is so difficult to make these sorts of decisions.

One final comment. I do agree with others that widespread acceptance in major police departments is a factor that must carry some weight. On the other hand I'm not convinced that a good SD round for home use has to meet all standard FBI barrier requirements. In particular I refer to the requirement that it perform well shooting through auto glass. While LEO do have to worry about that sort of thing, I expect I'll never encounter that situation. Indeed if the perp is fleeing in his car, unlike LEO, I can't legally continue the pursuit. The threat (to me) is over.

The point of the velocity test earlier in the thread is that the when fired from a 3" Kahr the velocity lost of the 147 load is very small compared to the service size pistol.

The 124+P and 147 Gold Dots are both recommended loads in 9mm here:

http://ammo.ar15.com/project/Self_De..._FAQ/index.htm

Now if you were using the 3" Kahr which load would you use?

The standard pressure load that is 33 FPS slower than out of a service size pistol.

Or the plus + loads that are 74 FPS (or in the case of the short barrel load 67 FPS) slower than out of a service pistol.

Also keep in mind one of the loads tested is Speers very own "short barrel load" which is only 7fps better than the standard +P loading in this test.

[MikeG]

A very good article, and one that helped convince me that 9mm is a fine substitute for .45acp a while back. Just keep in mind, the main advantage of speer's short barrel rounds is less flash and muzzle blast, a few extra fps is just a byproduct of the more efficient powder burn, which is not an issue in longer barrels. For me, I'll be just as comfortable with either the 147 or 124+p. Still running reliability tests tho so haven't decided yet.

[Benaiah]

I just ordered some 124gr HST's for my CM9. I can't wait to get them and test them. I couldn't find anything negative with this round.

[jocko]

I do think kahr does their testing and sighting in with these gun at I think 10 yards and with 124 grain ammo. what brand I amsure varies with price and availability..

[wyntrout]

Penetration could be very relevant if you're out for a walk and a car pulls up and the occupant(s) open fire on you. Being able to penetrate the door/windows would be very desirable in that UNLIKELY event... but STUFF happens... when you least expect it.

I try to avoid being the only available target... out for late-night walks... or early in the morning. I used to do it walking my dog... but I carried a P12 loaded with 12+1 230-grain Federal Hydra Shoks... 7 1/2 years ago... ammo is different now... sold P12 to get new HDMI-capable stereo for HDTV.

I found it interesting in some windshield penetration tests, that hollowpoints fared better than FMJ... digging in and going straight, instead of being deflected or diverted from point of aim.

Wynn