# hk USP 40 to 357 conversion



## steveinaustin

Hi all,

I picked up a usp compact in 40 this week (a 2001 model) and love it. I noticed hk has a drop in barrel for 357 for this pistol. Has anyone tried this conversion and can tell me if a simple barrel change is all that's needed to run reliably?


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## desertman

steveinaustin said:


> Hi all,
> 
> I picked up a usp compact in 40 this week (a 2001 model) and love it. I noticed hk has a drop in barrel for 357 for this pistol. Has anyone tried this conversion and can tell me if a simple barrel change is all that's needed to run reliably?


No I haven't tried it, but .40 to .357 Sig is a popular conversion. A simple barrel change is all that is needed. You can even use the same magazines. The .357 Sig is a necked down .40 case with a .357 bullet. About the only issue may be finding ammo for it.


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## Dodge

Hey I recently got myself a Hk usp compact in .357 sig. I love this gun and the caliber. Im curious tho, if this works the other way around? I see Hk has a .357 sig conversion barrel for the .40. Would I be able to swap in a factory .40 barrel? Thanks


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## Pandaz3

It is true with Glock and Springfield XD series and I would think the USP too. I have a USP 40 (Full size) I have a small G-33 in 357 Sig, and a Springfield XD357. Magazine for 357 Sig in the Springfield will not work using 40 as they have an additional crease in the fore part of the body to keep the bottlenose bullets inline.


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## pblanc

SIG Sauer uses the same magazines for both .40 S&W and 357 SIG. I don't know about HK.


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## Pandaz3

Yes I can use any 357 Sig or 40 S&W Glock magazine in my G-33, no difference except caliber stamp, function is identical.


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