AR-15/M16 Dedicated .22 LR Barrel
This video demonstrates the dedicated .22 barrel for the AR-15/M16 platform that is used in conjunction with your .22 conversion bolt.
WARNING: Never attempt to disassemble or reassemble a firearm unless you are absolutely certain that it is empty and unloaded. Visually inspect the chamber, the magazine and firing mechanism to be absolutely certain that no ammunition remains in the firearm. Disassembly and reassembly should follow the manufacturer’s instructions.