JJS,
I have found that Retumbo gives very uniform results in terms of no velocity variation due to changes in termperature.
I shot my pet Retumbo/200AB 300 RUM load over several weeks this past winter, in a temperature range of almost 40f (20f to 60f) and found little to no velocity change over that temp range.
Accuracy was outstanding. Very pleased with the results.
Tony.
