Wowzers.. can you say muzzle blast? .223 thru a 10" barrel=lookout! Had a good time at the range. Fired Tula (yes I know it's the dreaded steel case), Remington green box and some WWB I bought in 93. All ran well with zero issues. Started with the regulator 10 clicks out, then 9 and finally 8. Noticeable difference in recoil from 10 clicks to 8. This thing is a beast...For those in the Tampa Bay area Shooters Shack south of Plant City is NFA friendly. $15 an hour to use the range. Be prepared for an interesting last half mile to get there, and a "few" shell casing's on the ground.