Aero Precision .308 Carbine Buffer (3.8 oz)

The Aero Precision .308 Carbine Buffer is the short, fixed-weight buffer Aero builds for its M5 large-frame carbines. It weighs 3.8 oz and measures 2.5 inches long, and Aero lists it for .308 carbines with a collapsible buttstock. Aero is explicit about the limits: this buffer is specific to .308 carbines and will not work in .308 rifle-length systems or in AR-15s.

The short length is what lets a DPMS-pattern .308 carbine run an ordinary carbine receiver extension. Aero's own M5 .308 Carbine Buffer Kit pairs this buffer with a mil-spec 7075-T6 six-position buffer tube, a .308 buffer spring, an end plate, and a lock nut, so the recoil system behind the bolt carrier is a standard carbine tube with a shorter .308 buffer in it. Armalite-pattern AR-10 carbines are a different system: they use a slightly longer, non-standard carbine tube and a longer carbine buffer, so confirm which tube your rifle has before ordering.

Use this as the fixed-weight replacement when a .308 carbine buffer is worn, lost, or was swapped out during tuning. It has no adjustment, so a builder who needs to add or remove reciprocating mass on a suppressed or forced reset trigger build is better served by the ODIN Works AR-10 Adjustable Buffer, which tunes from 3.45 to 4.65 oz in the same carbine-length tube.