If you seal the cap with fingernail polish before you screw the nipple into the breech plug, make sure all excess gun oil is out of the breech plug and nipple first. The saran wrap on the end of the barrel is a good idea. I have a Knight. Last year I sat in a pretty good rain for 1 1/2 hours before I shot a doe that came along. I just had the cap on the nipple and covered the end of the barel. You might carry along a piece of plastic to drape over the breech plug area to direct water away while you are sitting in the tree stand. Have fun.