JP Enterprises AR-10 Carbine Length Tuned Buffer Spring

This JP Enterprises operating spring is sized for large frame (308 AR) carbine length buffer tubes. JP centerless grinds and polishes the spring, which makes it smoother and quieter in the tube than a typical rough wound buffer spring.

JP says the improved impulse feel helps sight recovery and reliability. JP also recommends this same spring for 9mm carbines, so it is worth a look on a pistol caliber build too.