Have some Tac. Looking at info, Nosler had best accuracy
at 42grs. Ramshot doesn’t have info for CC, but does for
the 155 Sierras at 41.1 start.

Anyone else play with Tac and the CC’s?
Not buying another powder, so not interested
with the 50 other powders that work well.

Thanks.

What is your end game?
Accuracy?
What type of platform?
If you are looking at 100yd range is one thing but to get them to 1k then you need a long bbl and
a muzzle velocity in the 2950/3000fps range for the 155 to be good to 1k.

They're very similar to Sierra's 155's and probably need to be closer to the lands to shoot best. 2950 fps +/- is generated from 30" bolt action Palma rifles, you can't safely get anywhere close to that.

Standard Palma loads using Sierra's 155's in Winchester brass is 46.0 to 47.0 grains of Varget with 155's jumping .010" or more. This is a 1000 yard tournament load.

I've never used TAC and as a rule avoid ball powders. Extruded powders tend to shoot better groups over a wider powder charge IME. There is nothing wrong with ball powders, I just prefer extruded.

IMR-4895
H4895
Varget
RE-15
VihtaVuori N150
VihtaVuori N140
IMR-4064

are all great powders for .308 match ammo.

DO NOT MIX Lake City military brass in with commercial brands, it's way too thick to use the same powder charges safely.