Back to powders and such, I used to shoot IMR 3031, then IMR 4064, then BLC-2, Then W748, then switched to R15. Somewhere there was some H335 as I recall, and maybe a few others. Now I shoot nothing but Ramshot TAC (but I may go back to some IMR 4064 for 180 Nozlers). I usually shoot 150 Sierra Matchkings, 45 grains of TAC, Federal Match primers, and both Remington and Winchester brass. Have Lapua on the way. I am shooting a factory rifle (Sako 75 Hunter Stainless) and groups are usually around one half MOA some a little smaller, some a little larger (Required some bedding and a little other work on my behalf). Best groups at 500 yards have been right at 3/8 MOA (little less than 2"). That's all with a six power scope. Anyway, the powder shoots really well with everything I have tried...Barnes x in 150, 168, and 180; Nozler Partitions in 168 and 180, Balistic Tips in 150; and Sierra MKs in 150 and 168. By the way, I'm getting 2800 fps out of a 22 3/8" barrel for the 150 MKs. As I recall, that is a little less than the manual lists as max. but it is max in my gun. I DEFINITELY suggest you always start a little low, especially if you work up loads in the winter when temps are cooler. Although, TAC isn't affected nearly as much by temperature as either 748 or R15. The IMR extruded powders are usually less affected by temp than the Ball types. I am not shooting as far as a lot of these guys yet, but I love my .308. Hope you enjoy yours as well. They are soooo pleasant to shoot! Good Luck.