My recoil system is a "hybrid experiment," so don't do it. It works for me on my handloads on 147s, but it didn't work with a solid charge of powder for the 140s - it's too heavy to cycle the 140s - but works like a champ n the 147s?... 5.7oz home-made 2.500" buffer, Sprinco Orange spring, mil-spec (verified) AR-15 Carbine receiver extension
Just run the Armalite AR-10 Carbine recoil system, and you'll be good.
Gas port on that barrel was 0.070". Armalite AR-10 Rifle gas tube, to get it right. Aero Precision NiB BCG, complete (which is just a ToolCraft Nib BCG). LaRue MBT-2S trigger. Aero M5 upper, lower, M5 rail. Generic 0.750" lo-pro gas block. LaRue LT-158 mount, 10MOA cant, 30mm. Athlon Argos BTR 6~24x50 scope, illuminated mil-dot reticle. AB Arms Urban Sniper Stock (the original one), with the optional butt pad. Vortex 30mm scope level. VG-6 6.5 Gamma brake. Springs, pins, all that jazz was Armalite parts, minus the Aero pivot/takedown pins. MagPul M-LOK bipod.
That's about it, soup-to-nuts, brother. Running the original MagPul SR-20 P-Mags. Fucking laser.
I feel that if the gasport was 0.080", it would run my 140gr load, on standard .308 Win match-type powder (Accurate 2495). It's doing so well with a Magnum powder (Alliant RL-22) and the 147s,that I'm not gonna change it, or drill that gas port. Sucks that I bought an 8lb jug of Accurate 2495 to run 140s, though. I'll use that 8lbs in some badass .308 Win loads...
There she is, brother...