For the ultimate buffer system performance in AR-15 PCC guns with barrel lengths of 8” or more, we recommend our Competition Package with our heavy damped 9mm hydraulic buffer (Part# RB5015HD), our 2.5 oz PCC Buffer Weight (Part# R15015098), and the SPRINCO Extra Power AR-10 carbine buffer spring (color code ORANGE - Part# SPRINCO-25762). In this package, the PCC Buffer Weight is placed in the buffer tube forward of the buffer, right behind the bolt. This package can be run in an AR-10/A5 length buffer tube for a full-stroke system which stops behind the bolt catch, or it can be run in a standard AR-15 carbine buffer tube for a system that is short stroked by ¾”. Please be aware that short stroking a PCC operating system may not properly reset some triggers and the bolt catch will no longer work with most bolts. Some shooters feel that the shot recovery is slightly faster with a short-stroke system, and it does seem to work well for many shooters, however, the recoil impulse is greater since the bolt has less time to slow down prior to impacting the buffer. It is our recommendation to set guns up in a full-stroke configuration for lower recoil, more reliable trigger operation and to retain the use of your bolt catch.