When selecting powders I usually follow this method. I check all of my load data sources and compile a list of the three fastest powders from each source. Then I narrow down the list by picking the 2 that are listed the most. I also pay particular attention to the accuracy loads listed in the Nosler and Sierra manuals. For the guns you listed, I4350, I4064, W748, H380 will all give you workable loads. I currently load for 223, 257 Rob, 6.5x55, 307, 30-06, 35 Whelen and my most recent addition a 270WSM so I'm forced to buy some new manuals. I have loads worked up for all with the exception of the 223 with every powder listed. 748 should work well for the 7mm08 and the 243. I4350 for the 270, 06 and 7mag.