I think you're on the right track in picking an 85 gr. bullet if you want one load for everything, as you stated. Barnes may be what you end up with, but you may want to try others as well. Some guns just get very picky about what bullet they shoot well.
There has been lots of talk and controversy on here in the past about 85 gr. slugs out of a .243 for deer. Some swear by them. You may want to do a search on here for that info................... Good luck with your gun.