what is the issue with 3 grooves and Amax
The issue is bullet blow-up especially in .224 and .243 barrels with 1-8" twist barrels with huge powder capacity, the problem becomes worse when you add in A-Max because Hornady has very soft jackets.
I know several people that shoot 223 and 223AI that swear by this combo with no issues, but in 22-250AI I got about 200 rounds through it and bullet blow-up started with the A-Max,got another 200 rounds with Berger VLD's then they started blowing up so finished barrel life with SMK's. with a 22-243 I'm guessing it would be even worse. I have seen this happen in at least 10 barrel's (4 of them my own) 8 were Pac-Nor,2 were Lilja.
I have switched to 5 groove barrel's and have not had one blow-up since and much longer barrel life. You will be OK with a Pac-Nor 5groove but I am currently running Bruoghton,Krieger and Bartlein. If you are interested in a carbon wrapped light weight barrel my gunsmith has been getting great results with the new Proof Research barrels that are now made completely in-house (spendy though).
