I have always used 150 BT in my 7RM for deer hunting and have had great success. On rare occasion, I have had a deer run a bit after a vital shot. It seemed like those instances the bullet penciled through and didn't leave much blood trail. One of my favorite hunting spots has helacious cover that I hunt the edge of. If the deer break into cover, the retrieval of the carcass can be maddening. Would dropping weight to 140 be of any benefit?