HK has these. They are rail-mounted like some other HK compensators for HK pistol.

Anyone have experience with these?

I think you mean HK Parts - a different company.

That's interesting. I've had some luck with one of those on an HK P30LS in .40 S&W but still seem to have significant muzzle rise in recoil. Basically the muzzle seems to jump about as much or a little more than it would for an uncompensated SIG P320F in 357SIG.

I never thought to look to see whether they had them for P320s. I get along better with the ergonomics of the 320 anyway so if those things are going at half price it might be interesting to pop one on the 357SIG just to see what happens.