OK, in a perfect world sealed is better than not sealed. None of my Black Hills .223 (68gr and 75gr)*, my Spier SBGD .38, or my HST 9mm (124gr and 147gr) have sealed case mouths, while only the Gold Dots seem to have sealed primers (blue ring around primer pocket).
Is there any reason to use an after market sealer (or nail polish, as I've heard this will also work) and apply sealer myself? Any reason not to? Can it cause more harm that it prevents? Can it even be done to the case mouth "after the fact"?
I understand that it is not necessary for ammo stored under "normal" conditions, but for long-term storage? This ammo does not get cycled through training - I have training rounds for that.
* Some of my earlier BH .223 (in the all red box) had red primer sealer, while newer BH (in the new red and black box) does not. I called BH and asked them about this and was told that all their ammo was sealed at the primer, but the new sealent was clear. I took this to be BS as other BH bullet weights in .223 were still being released with the "old" red primer sealer, but the 75gr OTMs had nothing.