hk usp compact 357sig conversion

[sandman]

currently own an hk usp40compact, and i'm interested in picking up a 357 sig conversion barrel. anyone have any experience with this conversion? would you expect point of impact to change significantly (may be an issue with my stock fixed sights)?

only two aftermarket barrels i can find are "jarvis" and "firedragon." barsto doesn't list the usp compact on their site. gonna check with hk this week to see if they carry an aftermarket barrel.