I don't know if it's been covered before, but has anyone used IMR Trail Boss with a 140gr. or 130gr. bullet with a chrono to establish a "Sub Sonic" load?
Follow their directions to get a starting load. I guess around 7.5 grains. Quickload says 7.0 in a 24" bbl with a 140 SMK is 1100 fps. I use 8.0 in a 308 with 150 grainers.