Use a solid rest at 25 yards to sight in. I use sand bags and I put duck tape on the one I fire off of to protect it from the flash at the cylinder gap. Off hand shooting is all some folks seem to do and at short range at that, reasoning no gun fight is going to be at 25 yards and you're not going to have a rest. Fine for practice, but you HAVE to know where the gun shoots. I need to optimise my equipment whether I have the skills to use it or not. You simply cannot tell how accurate the gun is any other way than to rest it at a standard range and shoot groups. Better yet would be a Ransom or other machine rest, takes all the operator error out of shooting groups.
If a guy tells me he can shoot 4" groups center mass at 10 yards with such and such revolver off hand, that tells me nothing about the gun. He's a reasonably proficient shot with a handgun, that's all I can glean from that information.
Our club used to have a ransom rest, but no one can seem to remember where it went or who has it. We only had K frame inserts for it, but I'd like to try my M66 4" in it with wadcutters. That thing shoots consistently into 1" for five shots at 25 yards with my wadcutters and I'm sure it'd shoot tighter, but that's about as good as I can shoot from sand bags with an iron sighted handgun. What I can say is, though, that revolver is more accurate than me. LOL It's an amazing revolver.
http://www.ransomrest.com/
