Exit is almost always bigger for me, depending on the bullet MUCH bigger. If the exit is the same size, I would switch to a softer bullet. If there was no exit(maybe from a small handgun?), I would switch to a stouter bullet. The only bullet I've ever seen for long guns that failed to exit was those P.O.S. powerbelt ML bullets. Pretty much every other bullet sold now expands well AND holds together like it should, making a bigger exit.
There seems to be a push for tougher bullets than needed, especially on deer sized game. These bullets make only a slightly larger exit. I suppose that would be better than a bullet that is too soft like a varmint bullet.