I have had 2-223Ai's. My previous barrel was an 18" bartlein 7.7 twist, It did'nt matter what I fed it, 75 & 80 eld-m was an easy button with varget. 26.0-27.0 which was compressed consistently a 3/8 moa gun. Now my current 223ai is a brux 7.5. Could'nt get it to shoot 75s or the 80elds. Tried 77smks they wouldnt shoot. Then I moved on to 80.5 fullbores and 80smks with 8208xbr and now its shooting really well. I would suggest trying some 80.5 fullbores with varget and or 8208xbr.
Sounds good. I will have to pick some of those up.
In my old barrel I was running 26 grains of bargain. Now I'm down at 24.5. what were you getting for velocity with the '80s out of your 18-in barrel with Varget and 8208? I'm at 2830 with an 80 ELD in Winchester brass.
whoops, my old barrel was an 18", current is a 20". I am at 2930 with the 80smks currently with 25.6gr 8208xbr. 20thou off. Its consistently a 3/8-1/2 moa. I was having issues with this new barrel with 75elds and 80elds. Get a couple of decent groups that showed promise and then was 1+ moa.