Hornady 55gr SP (2266), loaded to 2.200 per manual, mixed brass, CCI 400 primers
18" 1:9 barrel, temp 70F, 240m elevation
24.0 gr: 2856 fps (n=5), SD 30.93 (1.08%), ES 76
25.0 gr: 2969 fps (n=5), SD 19.07 (0.64%), ES 45
25.5 gr: 3008 fps (n=5), SD 13.82 (0.46%), ES 32