J P Enterprises AR-15 Spring Tuning Kit

The J P Enterprises AR-15 Spring Tuning Kit is a tuning accessory from J P Enterprises (brand part no. JPS4.0) built to let a shooter adjust action spring rate independent of the buffer weight. Retuning the spring changes how quickly the bolt carrier group returns to battery, which matters for reliable cycling with suppressed loads, subsonic ammunition, or unusual gas system lengths. It is sized to work with J P Enterprises’ AR-15 captured-spring and buffer systems.

Key Specifications

• It is a spring tuning kit for adjusting AR-15 action spring rate independent of buffer weight.
• Retuning spring rate changes how quickly the bolt carrier group returns to battery, aiding reliability with suppressed or subsonic loads.

Frequently Asked Questions

What problem does this solve? It lets you retune action spring rate to help the rifle cycle reliably with suppressed, subsonic, or otherwise atypical loads.

Does this replace the buffer weight too? No, this kit adjusts spring rate only; buffer weight is tuned separately.

Buy the J P Enterprises AR-15 Spring Tuning Kit

Order the J P Enterprises AR-15 Spring Tuning Kit through our gun parts and accessories selection at Schaefer Defense and we will ship it fast, fully insured, from our Lubbock, TX gun shop.