CMMG AR-15 Carbine Action Spring Mil-Spec Stainless Steel

The CMMG Carbine Action Spring is a Mil-Spec replacement recoil/buffer spring for the AR-15 platform, purpose-built for carbines running a carbine-length gas system. Manufactured by CMMG from stainless steel, this action spring is engineered to the same dimensions and tolerances as the original equipment component to deliver consistent, long-lasting performance in the buffer tube assembly.

As a key part of the buffer and spring assembly, the action spring works in concert with the buffer and buffer weight to control the rearward and forward travel of the bolt carrier group. Its rate and tension are calibrated specifically for carbine-length gas systems, providing the balance needed to ensure reliable cycling, consistent lockup, and proper ejection across a wide range of ammunition. The spring is compatible with most Mil-Spec AR-15 carbines and serves as a straightforward drop-in replacement for worn or out-of-spec springs during a build, refresh, or routine field service.

Whether you are assembling a new carbine from the ground up, refreshing a well-used rifle, or simply keeping spare components on hand, this CMMG action spring is a cost-effective way to keep your AR-15 running smoothly. The corrosion-resistant stainless steel construction holds up to long-term storage and repeated cycling, making it a smart bench staple for any AR-15 builder or armorer.