Receiver Extension and Stock Kit, Carbine, Mk3

The CMMGMk3 Carbine Receiver Extension and M4 Stock Kit has all the essentials for your next AR lower build. The M4 buttstock is a proven lightweight design that is extremely durable. Combine this kit with your choice of Lower Parts Kit to complete your lower group. All CMMG products are backed by our Lifetime Quality Guarantee. Kit Includes: 6-position M4 Buttstock CMMG 6-position mil-spec Receiver Extension (Buffer Tube) Buffer Tube Castle Nut Receiver Endplate .308 Carbine Buffer .308 Carbine Action Spring