I shot the 300 grn SST in my 50 cal GM LRH before. Typical load of 80-100 grains of FFG Swiss provided happy results. Never tried sabots in my 45 LRH barrel. It shot full bore lead with pleasing accuracy. If it were me I would start in the 75-80 grain range and work up from there. Not many deer gonna walk away from that in the boiler room.