Re: how wide are your nodes?
In my 7-08 with H-414, it's +- .2 grain or less. Very narrow. +- .5 grain doubles the group size. Varget appears to be slightly less sensitive, maybe +- .3 or .4 grains. Haven't shot it enough to be positive. My .30 x .378 is also surprisingly touchy. +- 1 grain of H-5010 (112 gr node) also doubles group size. Have just started experimenting with US 869. My impression is that it's not as sensitive, so I am concentrating on it.
Plausible conclusions: different powders can give a wider or narrower accuracy charge weight range, and a 1/2 percent total variation in charge weight is too much for these 2 rifles.
Good hunting, Tom
Texas State Rifle Association Life Member
NRA Endowment Life Member
A big fast bullet will beat a little fast bullet every time