Type: BB Air Pistol. Manufacturer:Crosman. Model:PRO77. Materials: Metal & plasctic. Weight: 1.3 pounds. Barrel: 4.1 inches, metal non-rifled. Propulsion: CO2 x1 (12 gram). Action: Semi auto single action only. Ammunition Type: 4.5mm steel BB's. Ammunition Capacity: 17 rounds. FPS: 325. The Crosman PRO77 I believe is Crosman's first modern blowback operated air pistol and they did a pretty good job with it getting most things right like a true single action trigger and working hammer, a discreet CO2 system, lots of metal parts where they really need to be and an overall good performer. Sure there is room for some improvement but as a first attempt it's a nice gun and not one that's going to set you back to much money either. I am looking forward to Crosman's upcoming blowback air pistol, the C51 that should be out in a month or two... Read full article here: https://www.replicaairguns.com/2011/7/27/crosman-pro77-co2-blowback-bb-pistol-review.html