I have 3 totally different 223 rifles, some of many good loads:

Savage 12 Target 1:9 twist, Rem 71/2 primer, 26 gr Varget, 75 A-Max or 77gr Berger VLD, LC brass. In BR stock 3"/1000 yards in factory over molded stock 5"/1000yards (Bullet touching lands)

Cooper 21 Montana Varminter 1:12 twist Fed 205M primer, 25.5 H335, Sierra 50gr Blitzking Win brass. over lapping (about 1/8" centers) at 200yds. (5-shot) (bullet touching lands)

1996 Bushmaster A-4 (flattop AR) 20" 1:9 twist (load from 1984) Mixed military brass, CCI Sm Rifle Mag primer, 26gr WW748, Win 55gr FMJ/BT w cannelure 5 shot group 1/4" centers @ 100 yards (fits AR mag)

All shot from competition front rest and bag rear, top has 8-25x40 Scope, both bottom with 6.5-20x40 scopes, all on max power and Adjusted Objective lens. WW742 & H335 "Meter like water!", I hand weigh all Varget loads.

Ivan