The Armaspec Gen 4 Stealth Recoil Spring (SRS) is a drop-in replacement for the buffer and spring in big-bore AR-15 (.458 SOCOM, .450 Bushmaster, .50 Beowulf) rifles. It’s a self-contained, multi-stage system that keeps constant tension on the bolt carrier. That gives smoother, quieter cycling and less felt recoil.
A standard buffer spring rubs and twangs inside the buffer tube, and the SRS spring never touches the tube walls. It installs with or without a buffer retainer. This version has an equivalent buffer weight of 5.7 oz.
Gen 4 removes the o-ring from the weight, adds a machined cap on the rod and uses 3/32 hex key screws. Bolt carriers with a rear opening under 0.60 inch won’t work with it. Compare the listed compatibility with the firearm in hand, since similar-looking components can differ by platform or generation. Browse more gun parts and accessories.
- Replaces the buffer and spring
- Multi-stage, self-contained design
- Spring never touches the buffer tube
- 5.7 oz equivalent weight








