Spikes Tactical AR-15 ST2 Tungsten Buffer

Product Description

The Spikes Tactical AR-15 ST2 Tungsten Buffer is a precision-machined buffer designed for use in AR-15 and M16 platform rifles. This buffer uses tungsten weighting to manage reciprocating mass and recoil energy during cycling. It installs in standard carbine buffer tubes and works with carbine-length gas systems to help tune performance.

Tungsten buffers offer higher density than steel, allowing more weight in the same physical footprint. This matters in tuning how your rifle cycles—particularly with suppressed fire, different ammunition loads, or adjustable gas blocks.

The ST2 designation indicates a specific weight class in the Spikes Tactical buffer lineup. Heavier buffers slow the bolt carrier group and reduce felt recoil, which can improve follow-up shot speed and reduce wear on components.

Key Facts

• Brand: Spike’s Tactical
• Model: ST2 Tungsten Buffer
• Firearm Type: AR-15/M16
• SKU: SPT-SLA00T2

How the ST2 Buffer Weight Affects Your AR-15

Buffer weight directly controls how fast the bolt carrier group moves rearward after firing. A heavier buffer like the ST2 slows the unlock timing and reduces the speed at which the BCG impacts the rear of the receiver extension. This translates to less felt recoil, less muzzle rise, and smoother operation—especially valuable if you run a suppressor or an overgassed barrel.

Tungsten weighting gives you more mass without requiring a longer buffer body. The ST2 fits standard carbine tubes and works with collapsible stocks, so you gain tuning capability without changing your lower parts kit or stock assembly.

If you’re experiencing cycling issues—short-stroking with a suppressor, or aggressive ejection patterns with factory ammo—swapping to a different buffer weight is often the simplest fix. Call 817-393-4000 if you need help selecting the right buffer weight for your specific build or gas system.

Compatibility and Installation

The Spikes Tactical ST2 buffer installs in any mil-spec carbine buffer tube for AR-15 or M16 rifles. It works with standard carbine action springs and requires no special tools or modifications. Simply remove your existing buffer and spring, slide the ST2 into the tube, and reinstall the spring and end plate.

This buffer is designed for carbine-length gas systems, though it can also be used in mid-length and rifle-length setups depending on your tuning needs. If you’re building or upgrading an AR-15, browse our full selection of buffers and buffer tube kits for complete lower receiver components.

Buying from Western Sport in Roanoke, TX

Western Sport is a licensed FFL/SOT dealer and gunsmith shop serving North Texas and the DFW area since 2007. Owner and gunsmith Lance Rankin and his team provide expert advice on parts selection, gunsmithing services, and firearm transfers. Visit us in Roanoke or call 817-393-4000 to place an order or ask about compatibility with your specific build.

Frequently Asked Questions

Q: What AR-15 rifles will the Spikes Tactical ST2 buffer fit?

A: The ST2 buffer fits any AR-15 or M16 pattern rifle with a mil-spec carbine buffer tube. It is compatible with standard carbine-length, mid-length, and rifle-length gas systems. Confirm your buffer tube type before ordering by calling 817-393-4000.

Q: How does a tungsten buffer compare to a standard carbine buffer?

A: Tungsten buffers use denser material than steel or aluminum, so they pack more weight into the same length. This slows bolt carrier velocity and reduces felt recoil without requiring an extended buffer tube or interfering with collapsible stock adjustment.

Q: Will the ST2 buffer help with over-gassing or suppressor use?

A: Heavier buffers slow the cycling speed of overgassed rifles, which can reduce wear and improve reliability when shooting suppressed or with high-pressure loads. The ST2 is a common choice for tuning rifles that cycle too aggressively with factory gas settings.

Q: Can I use the Spikes Tactical ST2 buffer with an adjustable gas block?

A: Yes. Pairing a heavier buffer with an adjustable gas block gives you precise control over cycling speed and recoil impulse. Many builders use both to fine-tune reliability across different ammunition types and suppressor configurations.

Q: Do I need any special tools to install the ST2 buffer?

A: No special tools are required. The ST2 installs like any standard carbine buffer—remove the stock, buffer tube end plate, action spring, and old buffer, then reverse the process with the ST2 in place. A receiver block or upper vise clamp can help if you need to torque the castle nut.

Q: How do I know if the ST2 is the right buffer weight for my AR-15?

A: Buffer weight selection depends on your gas system length, barrel profile, suppressor use, and ammunition. If your rifle ejects cases aggressively or shows signs of over-gassing, a heavier buffer often helps. Call Western Sport at 817-393-4000 for guidance on choosing the correct weight for your build.

Additional information