Varmint bullets in 257 blow big holes. Deer bullets blow smaller holes depending on placement.
I found this to be the case with the coyotes I've shot with the Roberts. Placement is critical.
A dedicated fur rifle is not always in the budget but if you're shooting fur and getting tired of sewing holes, how about saving all your fur from one season to put toward a dedicated fur rifle. Just a thought.
I used to put up fur on shares with several local callers when I lived in the lower 48. One of the guys was using his faithful 270 as it was the only rifle he had. I sewed up his coyotes for three years, some of which looked like they'd swallowed a grenade. The fourth season I told him he was saving his fur money for a coyote gun or finding a different fur handler. I even waived my share to help him out. He did and ended up with a 22-250. While not the best of fur friendly rifles for non handloaders, still much better than a 270. I'm not sure which factory load he finally settled on but he found one that was not too damaging. I want to say it was Remington's 55 grain SP but it's been 15 years since I was doing the fur handling. When I left for Alaska I know one of his buddies was helping him get started in reloading with the old Speer 52 grain HP. Several of us had great luck with that bullet on fur in Swifts and 22-250's.