Weatherby Vanguard .223 24" sporter barrel
Sierra Super Roo 55gr SP
WSR primer
AR2207 20.2gr.
12mm 3 shot groups @ 100m
AR2207 is fast burning, so a little slower out of the muzzle. My calculation is that I'm just sub-3000 fps. The rifle is 20 years old and I've put over 9,000 rounds through it. Probably 7,000 rounds using AR2207 (1 × 4kg container and around 10 x 500g bottles). I tried W748 (not bad, but much more cents per load) and BM1 (I never found a good load for my rifle, tried .2 gr increments). I found the Hornady Spire 55 gr soft point gave the most consistent grouping. The Sierras are a close second. Nosler soft points were terrible and Winchester ok.
Hornady Z-max 40gr with SR4759 / Blue Dot give great quiet fox and rabbit rounds.
My groups have recently opened up and I've either worn the barrel or getting long term fouling. I'm picking up a Weatherby Vanguard 20" varmint barrel this week to replace it. Looking forward to a shorter and heavier barrel for spotlighting. I'll also get a good bore cleaner to see if I can remove some copper and get a little more use out of my trusted rifle. Amazing for a "budget" rifle.
Don't overlook AR2207.