Tejano,
I just revised the list of cartridges I've loaded with Ramshot and Accurate powders, adding which powders have been used for the cartridges, and correcting a couple of memory mistakes.
As a more general note, I've tested the original four Ramshot powders (TAC, Big Game, Hunter and Magnum) at 0 Fahrenheit. In those tests Hunter was the most cold-sensitive, losing about 100 fps from 70-degree velocities in both a .257 Roberts and .30-06 load--but that is still better performance than many "traditional" powders, many of which lose 150-200 fps at zero compared to 70 degrees.
TAC has proven very temp-resistant in the .223 Remington and .308 Winchester, not surprising since those are the rounds it was originally designed for as a military powder. It can vary more in cold when used in other rounds.
Big Game has proven very cold-resistant no matter the cartridge, which is why it's my favorite Ramshot powder for, uh, big game cartridges. In fact, it may be one of those powders (such as Reloder 26) that's very temp-resistant even though not specifically developed to be.
Magnum has also been pretty temp-resistant in several cartridges.
Have not done much cold-testing with Accurate Powders, mostly because I primarily use 1680 in the .17 Hornady Hornet for prairie dog shooting, where heat is the most common problem. (Have also mentioned before that I have yet to find a temp-resistant powder that isn't affected by heat over about 80 F., though temp-resistant powders are affected less.) Tested my 1680 .17 load at 115 degrees, and it gained around 100 fps, though accuracy and point of impact remained unchanged--and there were none of the usual high-pressure signs.
I also use 5744 quite a bit as a smokeless equivalent in black powder cartridge rifles, where temperature isn't usually a problem.
