Type: BB machine gun. Manufacturer: RAP4. Model: RAP5 (H&K MP5). Materials: Metal & Polymer. Weight: 6-7 pounds. Barrel: 9.5 inches, metal non-rifled. Propulsion: CO2 or bulk air. Action: Semi & full auto, single action. Ammunition Type: .4.5mm steel BB. Ammunition Capacity: 21 round magazine. FPS: 400fps. When I heard about this BB machine gun, I new I had to have it and mostly because of the way it feeds and ejects the shell casings, much like a real gun! I'm also a big fan of the H&K MP5 styled rifle and PDW version. I was genuinely impressed with everything about this BB shooter; design, quality, realism and shoot-ability and I hope to one day get the RAP4 (M4 styled) version of this gun which uses the same feeding mechanism. If you want the most realistic looking and operating full auto 4.5mm BB machine gun you can get then this is really it. Read full article here: https://www.replicaairguns.com/2011/10/29/real-action-paintball-rap4-rap5-45mm-bb-mp5-machine-gun-revi.html Buy Replica Machine Guns in Canada: https://www.replicaairguns.ca/search?q=machine+gun Buy Replica Machine Guns in the US: https://www.replicaairguns.us/search?q=machine+gun