The Armaspec Stealth Recoil Spring (SRS) Gen 4 is a captured, one-piece drop-in replacement for the standard AR-15 carbine buffer and action spring stack. A multi-stage spring inside a sealed housing tunes recoil impulse smoother than a factory H1/H2 buffer while eliminating the tinny spring-slap you get from an unshrouded action spring — the entire recoil stroke runs quiet.

Specs & features:

• Captured one-piece design replaces both buffer and action spring
• H4 weight — heavier than factory carbine (H1), tunes hot loads and shorter gas systems
• Multi-stage internal spring softens felt recoil and impulse
• Sealed housing eliminates spring rattle and noise
• Drop-in install — no tuning, no shims
• Compatible with standard AR-15 carbine-length receiver extensions

Fitment: AR-15 with a carbine-length buffer tube (7075-T6 or 6061 aluminum). Not for rifle-length tubes or AR-10 platforms. If you are running a suppressor, adjustable gas block, or a 10.5"–14.5" barrel with a carbine gas system, the H4 weight will help slow the bolt carrier speed for cleaner cycling.