VPRS-15 Variable-Pitch Recoil Spring – Drop-In Upgrade for AR-15/AR-9 (Carbine Buffer Tube)

Upgrade your rifle’s internals with a true performance part.
At Pathfinder Militaria (“First Responder Owned & Operated”, Wisconsin roots), we’re committed to quality components that work as hard as you do. The VPRS-15 from Spike’s Tactical, engineered in collaboration with Cook Spring Co., is the only AR-15 buffer spring on the market built with a variable-pitch coil design.

Key Features & Benefits

Variable-Pitch Recoil Spring Geometry: The coil spacing gradually changes along its length, which cushions initial impact and progressively slows the bolt carrier group for a smoother cycle and less hammering on the receiver extension.

Drop-In Upgrade for Carbine Buffer Tubes: Works in standard AR-15/AR-9 buffer tubes, making it an ideal upgrade in both new builds and retrofits.

Multi-Caliber Friendly: Originally designed for 5.56 carbine tubes, the VPRS-15 also works phenomenally in 9 mm blow-back systems and .300 BLK builds—ideal for multi-caliber users who want consistency.

Lightweight Yet Durable: Weighs approximately 1.9 oz.

Patented Industry First: Marketed as the only AR variable-pitch recoil spring on the market.

Why This Matters

In tactical, competition, or duty setups—especially where suppressed, short barrel, or blow-back platforms are used—the recoil impulse and bolt carrier velocity play big roles in felt recoil, follow-up accuracy, and component stress. By slowing the carry rearward and reducing the “slam” of the buffer hitting the extension, the VPRS-15 helps a well-built AR feel more refined, shoot flatter, and behave more reliably.

Installation & Compatibility

1. Ensure your rifle is clear and safe.

2. Remove the stock and buffer assembly, extracting the standard buffer spring.

3. Install the VPRS-15 spring in place of the original, using the same buffer and tube unless otherwise specified.

4. Confirm there is no binding or unusual contact in the buffer tube.

5. Function check, then live-fire to verify cycling, ejection and reliability.

Note: While compatible with most AR-15 carbine and 9 mm blow-back configurations, always verify clearances, gas system tuning, and buffer weight for optimized performance.

Ideal For

• First-Responder / duty rifle builds seeking smoother recoil and faster follow-ups
• Multi-caliber users switching between 5.56, 9 mm, or .300 BLK builds
• Anyone upgrading a standard carbine buffer system for improved cycle feel
• Wisconsin shooters and Midwest range-rats wanting American-made quality backed by a lifetime warranty

Pathfinder Militaria Promise

When you purchase from Pathfinder Militaria, you’re buying from a First Responder Owned & Operated business with Wisconsin roots. We stand by every part we sell, we understand the duty-grade mindset, and we ship fast from the USA.

Specification Table

Spec — Value
Material — Steel (Variable-pitch coil)
Weight — ~1.9 oz
Compatibility — Carbine buffer tubes (AR-15/AR-9/.300 BLK)
Warranty — Lifetime (Spike’s Tactical)
Manufacturer — Spike’s Tactical (USA)