all my guns, if i hunted in rain, i use spray oil that you like, i use sheaths and spray under sights and peeps and the actions etc.

i take stock off when i do this.

shotguns always rust under rib on top for example.

i dont remove scope/sights.

breakfree clp is one of best for inside barrel or actions in my opinion.

but i dont use it on the outside of barrels, i use sheaths or rem oil..

clp leaves a teflon coating which dulls finish on outside of gun,i dont like that.