Drop the weight ! Up the velocity! TTSX 100 grain from the 260 rem 3200 fps is the most effective kill pill i have ever used . Factory ammo is often slower than the box says in general in my experience . I have only had one stag run a significant distance ( 70 yards downhill) and the issue was placement , i miss read a channeling wind between two peaks !. 270 should wreck em with a lighter , faster TTSX, forget what the lead weight is for the cartridgeI'm finding same with 130 grain TSX in 270 with chest shots and the deer a running further IMO. The 130 grain Gamekings killed them more efficiently and left better blood trails. Like you said good experience for the dogs and a cleaner carcass with copper.