all depends on what your rifle likes Nick, Scotts scaffold pipe shows pressure signs with much above 43 grns N140 behind a 2155, my 20" barrel swallows 45Grns easily and looks like 46grns isn't going to be a problem, his load spits out at almost 3000, mine 26-2700, go figure! if you aren't worried about F class at 1000, then 2155's work great at 300,600 and will hold the target at 1000, even at slower speeds, you just won't win any long range comps against 260's 6.5's etc. 175 SMK's could be a goer, Danny is your man for getting the most out of .308