You really don't know what caused the problem unless you recover the animal. I shot an antelope a few years ago, broadside at 100 yards. She dropped to the ground, got up, ran around in circles and ran off. I couldn't find her. Blood coming a little over halfway up, in the middle of the lungs. An hour after giving up, I shot another one at 275 yards. She ran 100 yards and dropped. The bullet, a 103 gr Hornady ELD-X out of a 6mm Creedmoor, did not penetrate more than 3-4 inches. A lot of damage in 3-4 inches but that's not acceptable. So, now I use only Hornady copper bullets or Barnes TTSX in my rifles. Problem solved.
Addition: I've killed two antelope with a 22-250 using bullets that I would use for prairie dogs, Varmageddons. The bullets penetrated much better than the ELD-X on that antelope.