All depends on the value of the shotgun. I used the Mossy Oak Graphics skins on my turkey gun umpteen years ago and it’s still there and good. I’ve never understood painting a rifle, lol. It’s a rifle, if something is that close to see what you’re carrying you could use a shotgun. Only reason for the skins on my turkey gun is it was wood and not synthetic.

this is an 870 express under the camo paint
the Express metal finish rusts if you don't keep it nearly wet with oil , it's like a 2008 Chevy Colorado Frame in NE IA without fluid film.

so getting blood all over it would be a reason to break out the oil can right away and start getting it off.

but now when it is painted it is a non issue.
this gun got blood all down it this year