The Rifle Length Modstock is a dual-purpose stock system which mounts to either a Carbine Collapsible Receiver Extension (Mil-Spec only) or the Rifle Length Receiver Extension. This stocks is the M16A2 length which is 5/8-inch longer than the M16A1 length.  Both flat cheek pieces and battery compartment cheek pieces are included.  Buttstock also come with one QD push button sling swivel that will fit in the left or right sockets located near the rear of the stock.  

When mounted to the Rifle Length receiver extension the stock will be the fixed at the A1 length. When mounted to the Carbine Receiver extension the Rifle Modstock can be adjusted for length by using the Carbine Receiver extension’s locking positions and the provided locking pin.

All rifles use the same receiver extension tube; there are no Mil-Spec or “Commercial” diameters.  The A2 rifle uses a 5/8” spacer and longer screw. The A2 length Rifle Modstock kit does not come with the longer screw or A2 spacer.

Note: When mounted to an adjustable receiver extension tube the Rifle Modstock is legally considered an adjustable stock!