Umarex HK 416 177 Caliber Air Rifle - Bring your BB plinking game up a level with the HK 416 177 Caliber BB carbine. This officially licensed BB blaster is powered by easy-to-find 12 gram CO2 and has a drop-free magazine that holds 500 BBs in its main reservoir and 36 BBs in the feeding portion. Reloads are fast and CO2 changes are very easy with this system. The HK 416 BB carbine is loaded with plenty of Picatinny Rails for the attachment of optics and accessories. FEATURES: 177 Caliber BB Single Shot or 6-Round Burst Operation Powered by two (2) 12 Gram CO2 Cartridges 36 BB Internal Feed Magazine 500 BB Reservoir Flip-Up Iron Sights Included Adjustable Stock Full Length Top Picatinny Rail Side and Bottom Picatinny Rail Quad Rail Trigger Action: Single