Where I deer hunt it often rains. I usually seal the primer pockets with a small dab of nail polish and rub the exess off immetidately, leaving a tiny ring of lacquer that seems to seal well. Meaning, I've never had a failure to fire. Come to think of it, none of my un-sealed ammo has failed to fire either. ??
the only reason to seal rounds is for long term storage outside vacuum sealing. or when you know the rounds are going to be subject to longterm submersion as in hunting in a swamp or maybe survival. typical hunting non-survival style its not needed.