10mm is an interesting round for sure.
Speaking of Uncle Ted and his 10mm...the one I saw him shooting on the tv last night was a Springfield Armory 1911 with what looked like a 6 inch barrel and adjustable rear sights. He shot an axis deer at about 90 yards and hit it a bit far back. Tracked it down and hit two more times out of about 5 or 6 shots fired...don't know for sure but he reloaded...from those two hits it was a heart shot and a shoulder shot. Dead deer. Personally I think his first shot was too far but that's just my opinion.
Don't know that I'd use iit for bear unless it was all I had as a sidearm and I didn't have my rifle...
BTW...mature bull elk are way over 290lbs....cow elk are around 3-500 lbs...Bulls run 700-1000 lbs. Yearling bulls may be around 300 lbs or so. Elk are very muscular, dense animals with a heavy bone structure. If you hit the V perfect you are OK. HIt the leg bone or that shoulder blade and not so much....I'm still talking handguns and bows here; heavy rifle calibers will break down a bull with that shoulder shot.
And, with Ted's class III, he had a MP5 in 10mm that rocks.