Paul I am not sure I would want to stuff anything into my bore due to the possibility of increased pressure. The tape, ballon or whatever are on the exterior so this is a non issue but when you put a foam ear plug inside you could be asking for trouble.

BC, you might be right and I don't know b/c I tape my bore all the time. The main reason is to ensure they don't get mud, ice, snow, etc in them, b/c of the area/enviroment and I only hunt on the ground. It is just become a habit for me, like putting on your wooly's. It may not do anything 99% but the 1% is why I don't chance it.