Primer sealer is a solution to a problem that doesn't exist. The press fit of a primer in an UNDAMAGED primer pocket, is very water resistant. ANY liquid would have to be under a lot of pressure to overcome that press fit. Meaning; very deep dives in a lake or ocean. A simple raindrop or a soaking rain has no pressure other than atmospheric pressure, it won't get a primer OR the powder wet.
Bullet fit in a clean neck and undamaged bullet shank is also very resistant to moisture.BUT the military seals both the bullet and the primer for those what-if situations. What if a Navy seals team deploys from a submarine to a shore landing? I don't know if the weapons are inside a waterproof pack or if the ammo is also. That might result in water seepage, so the ammo has the primers sealed.
The more people I meet, the more I love my dog
They're going to get their butts kicked over there this election. How come people can't spell and use words correctly?