Not sure of Temp variations, but I started using Reloder 15 in a .22-250 last spring and at starting loads was plenty accurate for reasonable range Groundhoggin'.
Soon I'll be running it up to, closer to max load and see what it does.
I may try it in the Swift and .243 also.
I have not used the reloder powders just because a friend with tons of reloading experience told me that it was pretty temp. sensitive. I dont know for myself just passing along what someone else with many more years of exp. than myself said.
RL-7, RL-15, RL-19, and RL-22 are the most accurate powders for many rifles I have;
RL-7, for 222, 223 and 222 Mag
RL-15, for several of my 7mm chamberings
RL19, for a 244 Rem
RL-22 for a 25-06
I use RL-7 in my .221, works better than anything I've tried to date. Excellent accuracy, meters like water and a little goes along way.
I use RL-10x in three different .204 Rugers and its my first choice in that chambering.
RL-15 is a perfect mid range chambering powder although it doesn't meter that great it is very good in several guns I load for. I keep all three on hand all the time.