I am about to start load development for a new rifle in 300 RUM. I have more that one rifle in this caliber and have been handloading for this caliber for some time with my go to powder being RL 25 with which I have had fantastic results. The problem is I will be doing back to back hunts with temperatures for the first hunt in the 5 to 35 degree F range and temperatures for the second hunt around 70 to 80 degree F, so temperature stability is a desirable powder characteristic. This is not an especially strong attribute of RL 25. I am looking at in order of preference: Retumbo, H1000 (excellent results for me for 7mm RUM), and US 869. I know there are a number of forum members that shoot this caliber and am soliciting your experience with these powders in 300 RUM. I will be using 180 gr bullets - either Barnes TTSX or Nosler AB. Thanx in advance.