I also hunted Thursday and it rained heavily all day in the area I hunted in. I actually had the same worry as you did, but didn't have any tape to put over the barrel. I tried to keep the barrel pointed downward when walking, and when sitting I did sit in a covered stand. I didn't see anything that I could shoot at, so I left it loaded. I decided instead of unloading it that I'd just leave it loaded since I was going back out Friday. I was worried moisture would have gotten to the powder. I did change primers on them on Friday. Anyway, that afternoon I ended up seeing the biggest buck I've ever seen and I decided to take the shot as he was getting ready to head back into the woods. The bullet had the exact POI I wanted it to and hit exactly where I aimed. So luckily for me, it worked out well. I think the key is to just keep your muzzle pointed down. If you are really worried about it, put some tape of the barrel.