DPX better for short barrel?

E

Elerius

New member
I ordered a Kahr PM9 and am looking for carry ammo to use in it. I carry Gold Dot +p 124 grain in my K9. Speer makes the Short Barrel for 3.5 inch barrels in particular and so I wonder about that, it supposedly is designed to expand more reliably with the lesser velocity from shorter barrel lengths.

Putting aside the question of whether 1/2 inch of barrel difference necessitates a whole different type of "short barrel" just to expand reliably, what I WOULD like to figure out is if Cor Bon's DPX all copper bullet would be more likely to expand more reliably from a short barrel like the PM9 when compared to any others of the jacketed variety. Short Barrel Gold Dots can't be had anywhere on earth right now anyways so it would be between that and the normal 124+p that I already use.

I ask this partly because in researching DPX for the .32, it is able (according to Cor Bon's specs) to make 1050fps from a 2.5" barrel which I suspect comes specifically because the bullet is copper. (by that I mean something about producing the bullet in the way that they do because of its material and weight.) It would stand to reason I might get much higher velocities from the PM9 because of this then with any other kind.

I know that "you cant go wrong with both" but I would like to know your thoughts on the particular properties mentioned, even if just out of curiosity. No one talks much about DPX except to say that its promising.
 
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I mention the .32 because I have some of it but have never fired it. I gave up on the Tomcat line but that is what I was researching. I would be carrying a Kahr PM9 in 9mm from now on. In any case, that link doesn't contain any info on DPX, only for Cor Bon's JHP which is a normal lead bullet with a copper jacket.

I guess the simpler question is: Does DPX have inherently higher velocities even in short barrels compared to conventional jacketed hollow points, and if so, what is it about that particular design or material that makes it so?
 
Basically, the difference in rounds designed for short barrels is how fast the powder burns.

Standard cartridges are designed to achieve factory spec velocities and penetration from 4"-5" barrels in most cases. When fired from subcompacts and snubbies with 2.5"-3.5" barrels, those rounds suffer a loss in performance impacting penetration and expansion. The powder simply does not have enough time in the barrel to fully accelerate the bullet.

Rounds designed for short barreled handguns overcome this by using faster burning powders and/or bullet design to get the bullet up speed for adequate performance.
 
Putting aside the question of whether 1/2 inch of barrel difference necessitates a whole different type of "short barrel" just to expand reliably...
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The 124gr +P Gold Dot "Short Barrel" load is identical to the 124gr +P Gold Dot load. There's NO difference in propellant or projectile.

I load my PM9 with Speer 124gr +P Gold Dot.

what I WOULD like to figure out is if Cor Bon's DPX all copper bullet would be more likely to expand more reliably from a short barrel like the PM9 when compared to any others of the jacketed variety. Short Barrel Gold Dots can't be had anywhere on earth right now anyways so it would be between that and the normal 124+p that I already use.
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CorBon is loaded with the Barnes Tac-XP all copper bullet. The same bullet is also loaded by Black Hills and Barnes. Of the three the Black Hills load is the best, followed by Barnes. CorBon would be my absolute last choice.

According to Gary Roberts ("DocGKR"), "The lightweight all copper Barnes bullets are a good choice for shorter barrel pistols." See - http://pistol-forum.com/showthread....ut-short-1911s&p=202491&viewfull=1#post202491
 
The 124gr +P Gold Dot "Short Barrel" load is identical to the 124gr +P Gold Dot load. There's NO difference in propellant or projectile.
Click to expand...

This is interesting, information on the exact difference of standard Gold Dot and the Short Barrel has been pretty elusive. The only consensus I've read was that the bullet was made to expand at lower speeds then the normal Gold Dot.

Do you have a source by chance? If there truly is no difference, I find that to be a very underhanded marketing gimmick and does not endear me to Speer
 
" no difference" ?? Are you sure ? Minor differences can make a huge difference in perfomance !
In the early days of HP design , in the '70s Speer started out with a45acp bullet RNSP, then a RNHP with 1/16" hole,[these would maybe expand if you hit a rock ] ,then introduced the 'coffee cup" bullet with a 1/4" hole .That had a jacket scored in 12 places .A chuck hit in the shoulder/spine area would not have an exit hole. They then went to an unscored jacket which would exit a chuck.
I'm carrying Corbon 95 gr 9mm [standard pressure ] .I does make a serious dent in 1/8" steel plate but I haven't tried on chucks yet.
My experience on deer ,about 250 lbs, with 44 mag revolver and 45-70 rifle is that they work very well ,and I'm happy with them.
 
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