The Grendel R31 is a semi-automatic carbine that shoots the .22 Winchester Magnum cartridge.

In More Detail

The 30 round detachable box magazine is housed in the pistol grip. It also has a skeleton butt that can be extended using the two tubes that are housed on either side of the receiver. Most are equipped with a muzzle brake

Muzzle brake

Muzzle brakes and recoil compensators are devices that are fitted to the muzzle of a firearm or cannon to redirect propellant gases with the effect of countering both recoil of the gun and unwanted rising of the barrel during rapid fire...

and telescopic sight.