I tried all the recommended powders (IMR 4350, IMR 4064, H 4831, H 4350, WIN 760 and Re22) in my Ruger M77MKII with 100 grain bullets and could not be happy with the results (1 1/2" to 1 3/4" three shot groups). Read an article in Handloader a few years back by John Barsness (Mule Deer here on the forum) where he recommended the Barnes 100 TSX with 47 grains of Ramshot Hunter in the Bob - BINGO - finally a powder that would shoot a 100 grain bullet in MY cantankerous .257 RBTS (1" or less consistently). I tweaked the load and ended up with a COL of 2.800" using the Barnes 100 TSX, 46.5 grains of Hunter, GM210M primers and R-P brass - clocks 2900 fps in my 22" barrel. If the other recommendation don't work give this load a try.
