Got a .308 ORC on Monday, shot it with about 60 rounds of various surplus 7.62 as well as some Magtech .308. No malfunctions using LR20 mags, felt a bit overgassed.
Swapped the commercial receiver extension for milspec, knocked out the pins and removed the shaved FSB, added an Armalite clamp-on FSB (for now) and a bunch of Magpul furniture. Also swapped out the 5/8x24 threaded A1 flash hider for an A2.
Curiously, the gas tube rides ABOVE the barrel nut teeth, so Bushmaster just torqued the barrel nut to spec and left it slightly off kilter. However, since the MOE handguard indexes to the barrel nut teeth, I had to crank the nut a tad tighter to get everything lined up. No big deal, just something to note.
I will eventually have Adco drill and pin a new F-marked FSB. Why not just wait for the Bushmaster MOE .308? Well, I wanted the FSB to be correct and perfectly aligned (which Adco will do for sure) and I did not want the MOE stock, greatly preferring the CTR instead. These .308 ORCs do feature the lowered top rail DPMS uppers, so an F-marked FSB should line up correctly.
Weighs 7.8lb empty, 11.8lb as pictured with a full LR20 mag. That, to me, is entirely reasonable for a .308 AR.
