Parts kit
A parts kit is a kit of firearm parts without the receiver. This is due to US gun laws that consider the receiver the "gun" part of the firearm and the part that is regulated. This is different from other countries where pressure bearing parts such as bolts, barrels, gas pistons are the regulated parts. In addition to this US gun laws consider a receiver that is legally a machine gun cannot legally become semi-automatic. Thus the other parts can be sold together and a semi-automatic receiver purchased or manufactured to complete the firearm. Parts kits are available for many firearms including the AR-15 and AK-47.
