How much does the can weigh?
you should be able to make it work with a P9s (they are possibly the best HK pistol platform to suppress), or mabey a P7, although they don't suppress very well (due to fluted chamber)
Without a LID/Booster, you can't use it on the USP, or any other browning short recoil operated type pistols at ALL. Mabey a 1911 in 9mm, but im not sure... The problem is, it will not cycle because of the weight keeping the barrel from rotating up, and it will slowly damage the frame, because they slide will not unlock.
If you have a P9, or some other FIXED barrel gun (like a Beretta) it should work just fine, BUT, you'll have to get a 3-lug adaptor that screws on, although i think several people have, or can make them.