UPDATE:
Killed another 6 point the next morning, about 50 feet from where the other one was shot. I set up in a different place, this shot I estimate at 60-70 yards. Bang-flop (well, more like Bang-flop-flop-thud, he collapsed at the shot and fell down a steep 15 foot creek bank. Ouch).
Almost exact opposite angle of the first one, bullet entered close the center of the rigjt shoulder, put about a 2" hole in the ribs on that side, took out the heart and put about a 1" dia hole in the opposite side ribs-- did not exit, didn't look for the bullet in all the um, soup.
I reserved judgement on the other shot because to be honest, I've been a woods hunter until joining this current club (which has a lot of cutovers), and have only shot 3 deer at that distance in all the years I've hunted. But I've shot a BUNCH at 50-100 yds, with several calibers, and I know exactly what my .308 load does at that range on identical or similar shots-- which is to punch right through, taking bone with it, and I've never had one fail to exit at that range.
So while the .280 certainly did it's job, I can't help but conclude after 3 deer with 2 different bullets that the .280 and the .308 are pretty different animals when it comes to terminal performance. Not that it's bad or inferior, but it sure seems to me to be different. I recall talking to the first hunter I knew how shot a .280, a Texas hunter who hunted the Hill Country. I asked him why he liked that over the .30-06, and he said, "The .30-06 knocks too big a hole, tears up too much meat...". This must have been what he was talking about.
So when I said "doesn't hit as hard", maybe "not as destructive" would be a better description.
Whatever the semantics, they're different, from what I can tell.
Rick