Have never lost a deer with .277 140 GR BTSP Interlocks to my handloads.
Shot a dandy 8 point this year at 401 yards from as verified thru Leopold rangefinder., The bullet struck the chest and travled 3/4 of the way through the deer and the bullet was recovered inside the skin, Text book mushroom with a bit more shank.
IMO they are highly accurate and deadly on game. I might give the SST Intelocks a try next year as they have a slightly better BC then the Soft Points for the longer shot opportunities.