Just about any time I've heard complaints from hunters about a failure with a .243, they admit that it was not a deer bullet used, or a bad shot. Most won't want to admit a bad shot.
I think a lot of it, and have killed quite a few deer with one, and a good hunting buddy will only use a .243. Just about any standard 100 grain bullet does good work.
How to avoid failures? Honestly, shoot em in the vitals just like you would with anything else.
On the mark IMHO. I grew up with a 6mm Rem & 100 gr core lock did the job over & over again, stay away from frangable varmint or target bullets & stick with a high quality100 gr core lock or perhaps a lighter monolithic like a Barnes TSXX would my be my go to option today.
Decided I wished for bigger caliber as I aged. Today 6.5 Grendel suites me well for large midwest whitetail.
