I've had deer DRT from fast expanding bullets through the lungs, launched from a .25-06 or a .270. The only deer I've ever had run off from a fast bullet was a doe that took a 100 grain bullet .25 cal in the armpit, but the bullet cartwheeled down and went out the bottom of her belly; she bled little and took 1/2 hour to find.
The last two does I shot were both quartering toward me, and I took the onside shoulder in both cases. One was with a .30-40 krag shooting a 180 Nosler BT, launched at about 2200 fps. Shoulder broken, one rib broken on the onside, two ribs broken on the offside, and the shoulder muscles cut on the offside. She did a big face plant at the shot, but still made it 50 yards or so.
The other was also shot in the shoulder with a .30cal 125 gr Nosler BT, fired from a .30-30 at ~2350 fps. She ran about 75 yards before piling up, about 20 feet from a fence, which indeed would have made recovery a problem.
I think I'm seeing why, 80-90 years ago, guys who grew up hunting with .30-30's and .35 Remingtons, were tickled as hell to get '06's and .270's.
