Blair, I have not used trail boss yet. Will try it once my 4759 runs out. I know a few that have in my club and they like it. I like 4198 after 4759. Use about 25 gr in an 8mm or 30-06 sized case. I have used 4198 in 7x57, 308, 30-06, 7.5x55, 7.62x54R, 8x57, 30-40, 7.65 Arg, 35 whelen, and 6.5x50. I have stuck with 4064 in my 6.5x55 rifles as I have not found a good 4198 load for them that seals the necks good enough.