I've been playing with the Barnes 36gr varmint Grenade, In a 16" AR-15 1 in 9" twist 223.
Reloader 7 , BL-C (2) , 2230, and IMR 4198 All produced 1" and under Groups with Reloader 7 being the best with a 5/16" Group. Thats three shots at 100 yards. The Load I ended up using was a near max load of BL-C (2) in a 05 LC case with a Rem 7 1/2 primer. I took the Carbine out last night Groundhog Hunting and had great Luck. Shot one at 165 yards head shot , Not much left . The Second was at 9 yards
Body hit Big exit. For under 200 yards I've found a new love. The wind has a big effect on the Long light bullet so take care with the wind. I was unsure when I started this venture if the 1in9" barrel would spin them to fast . I got my answer.