This is a replica of a Colt .45 (Peacemaker) similar to the guns that Roland brandishes. I have no idea what kind of wood the grips are on mine, but it's probably
Colt SAA Peacemaker Pellet Revolver, 7.5" Nickel | Airgun Depot
New Colt SAA Revolvers: Worth The Money? | Thales Learning & Development
Single-Action Revolvers: Best Buy Is Ubertis Cattleman 1873 - Gun Tests