Did you try Jarvis?
I think Ayoob said, the rifling in a 6" Jarvis will match velocity with an 8.85 MP5 barrel with same load. If true, not such a benefit for staying subsonic. Naked though, those are nice numbers for a sidearm. His was Magnaported like a hunting revolver, the effect of a comp without the presence of one, is another thing that interests me.
I'm trying to find out the thinnest G10 grips available, from the half dozen or so makers