HK USP Compact in 9x21

[Powder Burns]

I have a 9x19 that I was considering rechambering for 9x21. Is it possible to get the chamber reamed out for the x21 brass or is it not worth the trouble? I may just get a second barrel for the 9x21 and keep the factory one as is, in 9x19. The reason behind this is that I am bored, and want a little more power out of the pistol. My .45 was illegally confiscated and I don't feel like carrying a .44 magnum, but the 9x19 is just so anemic..

[Powder Burns]

(bumped to top)

I mean really, 20 threads a day about painting letters, installing sights and LEM triggers. Aren't there enough stickied threads on these subjects to preclude people from asking the same tired questions over and over?

Somebody has to have more insight than just tips on painting slides and what holster works best. </rant>

...didn't somebody rechamber a .40s&w USP in 10mm? This would not be as complicated as the 9x19 and 9x21 have the same cartridge overall length.

[mercedes560]

A 9x21 is just for countries that can't use millitary calibers (i.e. Italy,ect). It isn't really more powerful. 9x23 and 9x25 are,but that would be a pretty complicated conversion.

I'd either A: Just find a good 9x19 load.

Or

B: Trade for a 40s&w or 357 sig model

[Powder Burns]

I would have to disagree, there is a difference in performance. The 9x21 has a higher powder capacity = higher muzzle velocity.
Using AA#7 and 147gr jacketed bullets I can load a 9x19 up to about 7.2gr for a muzzle velocity of 1014. Using AA#7 in the 9x21 I can fit 9.2gr for a muzzle velocity of 1228.


It might seem minor to you, but taking a 124gr bullet to 1335fps is something a regular 9mm can not do.
Also, I don't want to trade out my 9mm for performance when I already own 10mm's, .44 magnum's, and .45 auto's.

[BIG_CHRIS_304]

TO RE-CHAMBER THE BARREL WOULD BE RATHER EASY. IT'S NOT THAT HARD. YOU CAN DO A HIGH SPEED I.D. GRIND OR YOU CAN DO E.D.M. ANY QUALITY MACHINE SHOP WOULD HAVE NO PROBLEM DOING THIS. I'VE TAKEN FACTORY .40 CAL BARRELS AND RE-CHAMBERED THEM TO 10MM AND I HAVE ALSO ADDED O-RINGS TO THE FACTORY BARRELS.TAKE A LOOK AT SOME OF MY POSTS ABOUT MY 10MM CONVERSIONS. THE ONLY OTHER THING THAT YOU WOULD HAVE TO DO IS MAYBE CHANGE YOUR GUIDE ROD SPRING AND POSSIBLY DO A LITTLE WORK ON THE EXTRACTOR OR THE EXTRACTOR SPRING. IF YOU DO DECIDE TO DO THIS CONVERSION PLEASE KEEP US POSTED. A "STEP-BY-STEP" WOULD BE NICE....THANKS, BIG_CHRIS_304

[orfeo]

If you can get a 9 x 21 barrel for it, that would definitely be the way to go. . .

[SIGtrarian]

THE ONLY OTHER THING THAT YOU WOULD HAVE TO DO IS MAYBE CHANGE YOUR GUIDE ROD SPRING AND POSSIBLY DO A LITTLE WORK ON THE EXTRACTOR OR THE EXTRACTOR SPRING. IF YOU DO DECIDE TO DO THIS CONVERSION PLEASE KEEP US POSTED. A "STEP-BY-STEP" WOULD BE NICE....THANKS, BIG_CHRIS_304You won't even have to do that. The .40 S&W's and 9mm Lugers use the same recoil spring, and the cartridge rims are the same. It sounds interesting, but you'll gain more velocity by just buying a .357 SIG (9mmx22mm).