All the Redfields are fully multi-coated, nitrogen purged, waterproof, and shock tested. If you don't mind the 1" tube, it's a quality scope.
Some people prefer 30mm tube diameter because it helps with light transmission, but with a 52mm objective, I don't think that will be a problem. It is really only a consideration if you're out in the woods before dawn every day, and until after dusk.
I haven't personally looked through this scope, but on paper it seems well worth the price.
Anyone who shoots a sabot bullet has had the problem with loading the next round with a dirty barrel we have all struggled with it.
Between muzzleloader shots I have done some research and testing on my own to find out what works for me for the next shot. I have been using a product called bore butter and when the muzzleloader is just sitting around I leave it caked in the barrel for protection. Have also found that if I lube my sabots with bore butter they really slide nicely down the barrel....