Emailing us is the best way to get through.
We cannot answer phone calls in real time and process orders.
Please email us and we will get back to you as soon as possible.

Orders may take 1-3 weeks to ship. 

This notice takes precedence over all individual item statuses.


Most importantly DO NOT USE
Flat wire springs
Braided wire springs
Captured spring systems with sharp edges.
All of these can damage your lower.

The KP-15 receiver uses a Carbine buffer and spring.
We are only referring to length with the word “carbine” here, not weight. Use whatever weight of carbine buffer you need for reliability and smooth cycling. Use whatever weight of carbine spring you need, so long as it is a standard round spring.

Reference the graphic below for tuning your system.

The JP Silent Capture Spring System is approved for use. Use whatever combination of spring and weight needed for your rifle to run reliably.

Pistol Caliber Carbines
9mm Blowback systems require a minimum buffer weight of 5.4oz to not damage the lower.
.45 ACP Blowback systems require a minimum buffer weight of 8oz to not damage the lower.

Rifle Length Buffers and Springs will NOT fit.  You do not need a rifle buffer to use a rifle gas system: