Just swap this drop in conversion with the bolt carrier group from your5.56/.223 chambered rifle and you will be ready to shoot .22LR. Ships without a magazine. 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.All Stainless Steel Construction. No magazine included.Works in most 5.56/.223 chambered rifles.** Since .223 WYLDE is NOT a mil-spec chamber, we cannot guarantee fit or function with our .22 LR Conversion Kits**