While working up a new bullet load in a new barrel I used some Lapua brass and some Winchester brass. The Lapua being 20 grains heavier. The loads were in 1/2 grain increments and I choose to use the heavier Lapua for the lightest charge.

Lapua with 155 Sierra #2156 (Thanks to SlowpokeSlim) and Varget in a new Rock Creek 5R 26 1/2" tube Velocity = 2871 SD 11, 1/2 grain more Varget in Winchester brass velocity = 2860 SD 7. Note these were 10 shot strings. FWIW the Winchester shot noticably better on paper, range 300 yards.