I read that (don't remember where I saw it) that the S&K J frame snubbies are the biggest sellers.
Add to that Ruger, and some of the others.
I attend a lot of matches and semi's seem to show up in more numbers then revolvers,
But if you throw Cowboy Action, its really hard to tell.
CPT USAR Ret
USAMU Sniper School Oct '78
Distinguished Rifle Badge 1071