I have always had a .243 and have used one on game ranging in size from Jack Rabbits to Deer with no problem. I think there are better choices for big game but the .243 is adequate when used within its capabilities.
Back in the 70s we hunted Jacks with Hounds and my favorite rifle was a Winchester M-100 in .243... it had a Scopechief II 2.5-8 with a flip up post and cross hairs. I used very hot loaded 80 grain H/Ps and shooting rabbits running at a couple of hundred yards in front of dogs was very challenging. We used mostly Beagles and only cut the big dogs loose if we got into coyotes which were just starting to show up back then.
That M100 in .243 worked flawlessly for me for many years and thousands of rounds. I remember shooting (off hand) a bic lighter off a fence post at 100 paces with it to win the bottle at deer camp once. That rifle with 100 grain SP's was very good at cutting the brush when deer hunting and took a few nice bucks out of Parry Sound when deer were scarce.
I sold it to a buddy in 79 when my wife got pregnant... he has used it successfully as his Moose rifle ever since. I told him it was not enough gun.... he just laughs at me. He has shot a lot more Moose than I ever will.
My latest .243 incarnation is a BLR with a 2-8 Bushnell, I don't use it much but I have shot coyotes with it out to 200 yards with 55 grain B/Ts. It will shoot the 55gr Noslers into an inch and 100 grain bullets slightly better.
I shot a big Timber wolf with the 55 B/T's in Bobcaygeon a few years ago. On the run with a part of a sheep carcass in its mouth, I hit it three for five running at around 175 yards. I took the first shot off the fender of the tractor and hit it right in the shoulder (It just stumbled and ran faster!) the next four shots were off hand and I broke its back leg and then hit it in the spine with the last shot to put it down.
I remember thinking that I wished I had my old semi and 80gr hollow points for that one.
