[Peabody]

I recently purchased a new H&K USP Compact in 9mm, and was wondering if I can convert it to the .357 Sig with a barrel and magazine change? I don't need all the technical explanation if I can't, just a thumbs or thumbs down. I already have several other pistols in .357 Sig and just trying to add another option to the stable.

 

[TooSixy-closed]

If you want to go the factory route, you will have to get a complete .40 slide (minus the barrel) and the .357 barrel. Then add the mags.

I am not aware of any drop-in .357 barrel conversion for the 9mm.

 

[Barth]

I recently purchased a new H&K USP Compact in 9mm, and was wondering if I can convert it to the .357 Sig with a barrel and magazine change? I don't need all the technical explanation if I can't, just a thumbs or thumbs down. I already have several other pistols in .357 Sig and just trying to add another option to the stable.

Thumbs Down.

General rule on caliber conversion is you can sometimes go smaller.
But going bigger can be very expensive.
357 Sig is essentially a necked down 40 S&W.
The rear case is the same size.
So OEM barrel/mag swaps usually work well (sometimes the mags are the same too).

 

[Peabody]

Thanks for all the great info. I will just have to put a 40 on my radar and than add the 357 Sig barrel.