I use standard Murom LR (ie Tula or Wolf, depends on who's repackaging) with RL23, no issues to 0 degrees C
6.5 x55 Bob Jourdan Ackley Imp.
Lapua cases
CCI 250
Rl-23 49.4gr
Precision Ballistics 142gr at 0.008" off lands
2940-2950 fps 30" Bart. 8tw. 80-96degF