Shoot it a couple times.
Clean thoroughly, maybe rub a nylon bristle thru the bore, then reclean.
Sight it in, hunt with it.
Won't be the end of the world.
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Worst case is that if fouls up quicker from now on. You can lap the bore with valve lapping compound on a patch, then switch to a metal polish. Seems like I used Fritz metal polish one time on a rusty bore.
After a little oil and a lot of patches with a brush thrown in here and there, I think I have it cleaned up. I haven't shot it yet but it looks like it will be ok.