BCM STOCK HARDWARE MOUNT KIT MILSPEC

Description

Building an AR-15 lower from scratch, or replacing worn hardware on an existing rifle, requires every component between the stock and receiver to work together within the same dimensional standard. This kit from Bravo Company covers that entire interface in one purchase: a six-position receiver extension, castle nut, end plate, carbine action spring, and a carbine buffer assembly. Everything is matched to the same Mil-Spec dimensions, so there are no fit questions when you go to assemble.

The receiver extension is machined from 7075-T6 aluminum rather than cast or lower-grade alloy. That matters in a buffer tube because the stock collar cycles back and forth against it under recoil, and the detent that locks each position takes repeated spring pressure over the life of the rifle. A machined tube holds those features to tighter dimensional consistency than a tube that is simply extruded and left unfinished internally — the inside surface stays smooth enough that the buffer travels cleanly without dragging.

On the buffer itself, the standard carbine weight included here suits most carbine-length and mid-length gas system builds running standard ammunition. Shooters running suppressed, or using a noticeably overgassed upper, can swap in a heavier buffer (H, H2, or H3) without replacing any other hardware in this kit. BCM offers those heavier weights as separate options at purchase, so it is worth knowing your gas system’s behavior before you order.

Stock compatibility covers Mil-Spec collapsible designs from BCM, VLTOR, LMT, Magpul (CTR-M), Stag Arms, and Colt, among others. Made in the USA.