I used to use my ISSI AR .223AI 26" 9 twist Hart-barrelled AR, and had great results to about 500 with the 69 Nosler. But i also had a "tactical" system established for it-- 4.5-14X Burris/Ball. Plex reticle, and Leica LRF. But i wouldn't take a 500 yd. shot in any kind of wind-- mostly am, or later pm hours when wind was typically down. I tried the 75 A-Max, and 70 gr. JLK VLD, but they were poor killers at 3000 fps mv when the range stretched. Truth is if i ever go back to it it'll be the 75/77's as they may have a better compromise between frontal area (for long-range expansion) weight, and BC.