CMMG's AR drop in conversion kit allows you to shoot .22LR with the bolt carrier group from your 5.56/.223 chambered rifle. Includes a 10rd magazine.
Specifications:

Type	Bolt Carrier Group
Model	AR
Slide Finish
Slide Material
Barrel Length
Barrel Material
Barrel Finish
Capacity	10
Stock Material
Stock Finish
Includes	Magazine
Max Capacity