The Ruger Vaquero is a six-shot single-action revolver 

Traditional western-style, hand-filling grip has long been acknowledged as one of the most comfortable and natural-pointing of any grip style

Caliber: .357 Magnum/.38 Special.44-40 Winchester.44 Magnum.45 Colt;

Fits the XR grip frame, Ruger New Model Single Six, New Model Blackhawk, Vaquero (with serial numbers beginning with 50-XXXXX), New Model Super Blackhawk with round trigger guard & Old Army. Fits single action without a lock, stainless and blued firearms. WILL NOT FIT Vaquero with serial numbers beginning with 510-XXXXX, New Vaquero, Bisley Vaquero, Bird's Head Vaquero 50th Anniversary Blackhawk, or Hunter models.
ruger vaquero