Lower Parts Kits Pistol Buffer Tube Assembly w/ T-3 Buffer$94.95.308 Buffer Tube Assembly$89.95.308 Billet Small Parts Kit$39.00Pistol Buffer Tube Assembly$94.95Mil-Spec 6-Position Buffer Tube Assembly$94.95Standard Lower Parts Kit$45.00 – $85.00Enhanced Lower Parts Kit$127.00 – $181.00Magpul CTR Mil-Spec Complete Kit$148.95.308 Standard Parts Kit$74.00Spike’s Complete M4 Stock Kit$124.95