My experience is similar. In my service rifle I had to bump the charge up to 25.3gr to get the velocity where Varget would be more like 24.5gr.In 223 with heavy bullets, it's significantly slower burning than VarGet and MVs were on the low side needing an extra 0.6gn to provide a match. (A significant increase in the cartridge even in a long-throated chamber.) In 308 and similar, the pair appear to be closer, so 6BR is likely to be in-between.