Just swap this drop in conversion with the bolt carrier group from your 5.56/.223 chambered rifle and you will be ready to shoot .22LR.  Ships with Three 25rd 22LR magazines.  For best performance use a round style hammer as notched hammers can cause function issues and 36 grain plated nose bullets have proven to be the best choice for function.

Features:
All Stainless Steel Construction
Includes (3) - 25 Round Magazines
Works in most 5.56/.223 chambered rifles