MRI's Magnum Lite has a receiver CNC-machined from a 6061-T6 aircraft aluminum forging and features an integral Weaver-style rail for optics. The bolt is manufactured from heat-treated 4140 steel with tight bolt face depth tolerances for better accuracy. All Magnum Lite barrels have an 11-degree crown and utilize a 10/22 trigger group with 10/22 rotary magazines. A 22 WMR, it has a patented gas system and block under the barrel that taps a small amount of gas through a hole in the barrel. Note: The 22WMR is designed to shoot 40-grain and 50-grain ammo ONLY. This model features a patented graphite barrel, unique to MRI, which provides lighter weight, better heat disposition than steel, and is extremely stiff. It has a 19 barrel, black Hogue overmolded stock, and includes a 9-round magazine.