Features:

Short .308 Buffer Design: Built specifically for short AR-10 / LR-308 buffer systems where standard-length buffers won’t work
Improved Recoil Control: Optimized mass helps slow bolt speed and smooth out the recoil impulse in large-frame ARs
Reliable Cycling: Designed to improve function and consistency in properly tuned .308 builds
Drop-In Installation: Fits compatible short .308 carbine buffer tubes—no modification required
Durable Construction: Built to handle the higher forces generated by .308 platforms
Spike’s Tactical Quality: Backed by Spike’s reputation for hard-use, reliable components

Specifications:

Material: Stainless Steel Body with Tungsten Weights
Finish: Black
Weight: ~5.8 oz.

Compatibility:

AR-10 with carbine buffer tube

Details:

A .308 AR can be perfectly reliable and still feel rough if the recoil system isn’t matched well. When things are a little too fast or too harsh, it can feel like the carrier is hammering the back of the buffer tube every shot. The Spike’s Tactical ST-X1 .308 Buffer is built to take the edge off that cycle with a simple, drop-in buffer that focuses on controlled movement and consistent operation.

Sliding Tungsten Weights That Soften the Cycle

The defining feature of the ST-X1 buffer is its internal sliding tungsten weight system. Instead of everything stopping abruptly at the rear of travel, the moving mass helps manage deceleration and smooth out the recoil stroke. In practical use, that often shows up as less of the sharp “thunk” in the receiver extension, a more settled sight picture after each shot, and a rifle that feels steadier when you pick up the pace.

Stainless Construction with a Practical Bumper

The buffer body is stainless steel with a matte black finish, built to handle the extra energy a .308 carbine system brings. A Mil-Spec style bumper helps absorb impact at the end of travel, which can reduce stress on components and keep the action feeling less abrupt over time. It’s not flashy—just a durable design choice that makes sense for a harder-hitting platform.

Straightforward Fit for .308 Carbine Recoil Systems

The ST-X1 buffer is intended for AR-10/LR-308 pattern rifles that use a carbine-style receiver extension and recoil system. Installation is exactly what you’d expect: swap buffers, verify function, and confirm reliable cycling with your usual ammo. No tuning rituals, no new parts required, and no need to rework the rest of the rifle just to get a smoother feel.

A Small Change You Notice Immediately

If your .308 AR feels sharp, noisy in the tube, or just more violent than it needs to be, the ST-X1 is the kind of behind-the-scenes upgrade that pays off quickly. It doesn’t change what the rifle is—it simply makes the recoil system feel more controlled every time you press the trigger.