The Umarex Black HK MP5 A5- 6MM has a full metal upper receiver and barrel assembly with a tough nylon polymer lower receiver and handguard. THis airsoft gun holds 200 rounds so youll always be prepared. It has an MP5 collapsible stock and fires in the velocity range of 370-390 fps with. 20 gram airsoft BBs and has adjustable hop-up. Velocity: 370-390 fps Measured with. Length: 19.7″ collapsed /26″ full length. Weight: 6.2 lbs. Inner Barrel: 8.3.