Drop-in captured-spring recoil system helps your AR function more smoothly and quieter without any permanent modifications. The carefully balanced, custom-ground buffer spring, combined with the JP LMOS buffer, greatly reduces friction and vibration - say goodbye to the annoying “spoon over a cheese grater” noise of conventional springs and buffers. Fits buffer tubes for both M4-style collapsible stocks and also, using the included spacer, the longer tubes for fixed rifle stocks.

The Heavy Spring System Version have Tungsten Weights and are recommended for Short-Barreled Rifles, Suppressed Weapons, Rifles with an H2/H3 Buffer, Select-Fire Rifles, and Piston-Operated Rifles. 

The Alternative Spring Pack Kits are a pack of 3 different spring weights for the JP Silent Captured Spring that allow custom tuning of the device to a given rifle. While the default spring offers the best performance for the widest range of configurations, a simple disassembly and reassembly of the JPSCS-10 with a slightly different spring rate can yield truly optimized performance, particularly for rifles without an adjustable gas block. The Spring Packs are available separately or with a Standard or Heavy Capture Spring.