Originally Posted by
megasupermagnum
I used to seal all my hunting shotgun shells, as my main target was ducks and geese. All manufacturers seal their shells crimp for waterfowl hunting ammo, but few if any do for target ammo, or general purpose field loads. I'm not sure that any manufacturer seals shotgun primers, even the military rounds do not appear to have any sealer. Over time I began to question why I went through the effort, as I had never had a single round fail to fire. So I started testing without sealer. I quickly dunked un-sealed shells in water, and found perfect performance as always. I've always cut open factory ammo, and a surprising thing to note is that even on "sealed" ammo, there are a significant number that are not truly sealed at all. There are a lot of tiny gaps on a shotgun shell crimp, and sealing them is very difficult. I've not sealed a shotgun shell since, and still have yet to have a fail to fire on a shell. Once in a while I'll have one roll around the bottom of the leaky duck boat, but they too always fire. This year I had one that was completely under water all morning, as I had dropped it before light, and did not pick it up until I got back around noon. It too fired. A shotgun shell, with no extra sealing of the crimp or primer that had been on the bottom of a boat with standing water in it for 5-6 hours had fired as usual.
Now, I don't intentionally put my ammo under water. I actually go through trouble to prevent it. If I were a military, who may need to operate in the water, I would seal my ammo again. I doubt that sealing each cartridge has any bearing on the shelf life of the ammo. A standard cartridge loaded with no sealers, stored in half decent conditions has an indefinite shelf life, at least 100 years. Nobody knows exactly how long yet, as smokeless cartridge loaded ammo has not been around long enough to break down yet. My "spare" ammo gets stored loose in a plastic bag, a small desiccant pack inside, then stuffed into an ammo can. I use both the plastic and metal cans, and find little difference in actual use. Those plastic cans are tougher than you would think, and their only drawback is they wont handle a large fall. You could get more ammo in an ammo can if you stacked each cartridge carefully, but nobody has time for that. Loosely filled, I still get about 1.5x as many in as if they were in an MTM ammo box.