My club has a 2-gun and 3-gun match every month. The only divisions are rimfire and centerfire. You will see AK47s, M1As, Mini-14/30s, M1 Garands, Marlin camp carbines, ARs with scopes, red dots or just irons, M1 carbines, and SKSs. ARs are faster, but in the end, it all comes down to the shooter.