I'll second noKnees. Both TAC and Xterminator shoot well in both my 358 and 356 with excellent velocity. I shot a deer in December up here with my 358 at about 200 yards with the 200 Hornady and TAC with no issues. Ramshot says this about their powders:
Most of our powders are not insensitive, and will show some effect at hot and cold temperatures.
However, we test at -40F and +125F and the deviation in most cases are ca 3% to 5% at these extreme levels. Therefore most shooters do not notice much difference under normal practical hunting conditions.
More elaboration on the subject:
Complete temperature stability can only be achieved with tubular extruded powders designs, either with double base (NG) and/or with other coating technologies.
