I got a 7.5 AR (.223/556) build. Has a H3 buffer and the spring is 10 1/2 inch long( within spec) for carbine. Functions flawlessly, locks back on last rd and doesn’t feel like it’s to heavy recoil. It just throws the casings at the 1-3 o clock position indicating an over gassed system. Besides...
my gun smith told me he had a guy bring in 12 firearms to be cleaned. He charges 30 bucks to clean. He actually had to stop cleaning because he got so behind on actual gunsmith stuff