Who uses primer sealant?

J

JJ45

New member
I have some of the nail polish like stuff I use sometimes but don't really know if it's worth it. I don't follow directions as they say to paint the primer pocket before seating a primer but instead paint after seating.

I have a couple butt cuff equipped rifles and the cartridges are exposed and that's the main reason.

Also, most military ammo is sealed at the primer and case mouth for what reason?

Who seals primer pockets and case mouth rims? Thanks, JJ
 
I know one guy who had a primer killed by a water drop hitting it. Many primers are pretty resistant to a fast death from water or other solvents, but that is when they are just out ot the box. Seating can put cracks in the seal, and knowing the fellow this happened to, I expect his case was many times reloaded so there were probably scratches in the primer pocket and that pocket may have been on the edge of loose, so the primer cup couldn't get a good seal.

If you like the ammo cuffs, I would keep on using the sealant on the ammo to be carried that way to prevent what I just described.
 
Also, most military ammo is sealed at the primer and case mouth for what reason?
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They use sealant to keep stuff out, and to keep the bullet and primer in place. Same for using a crimp. Crimped and sealed, primers and bullets, its a "belt and suspenders" thing.

Military ammo is subject to a lot of vibration and possibly every liquid known to man. It HAS to work, so they go the extra mile.
 
Both primer and bullet are sealed in place to prevent water from getting inside the case ruining pellet and powder.

Next year on June 6th and you're watching movies of the Normandy invasion, note the rifle and pistol ammo troops fired ashore worked perfectly having been drenched in sea water.

Bullets are crimped in place to prevent shifting in abusive shipping and handling so the cartridge will chamber easily in the loading cycle. It reduces accuracy a little but the ammo is much more reliable.
 
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After the house fire of The Incident, my ammo stores were well wetted.
The USGI FCC 65 .45 remained tight and shot reliably.
The red stuff on Sellier and Belot was not an effective sealant, I pulled most of a case of 9mm for the bullets and cases because of a high misfire rate.
Aluminum Blazer was awful, burnt through cases eroding the chamber.
 
Jim Watson said:
After the house fire of The Incident, my ammo stores were well wetted.
The USGI FCC 65 .45 remained tight and shot reliably.
The red stuff on Sellier and Belot was not an effective sealant, I pulled most of a case of 9mm for the bullets and cases because of a high misfire rate.
Aluminum Blazer was awful, burnt through cases eroding the chamber.
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Wow, interesting post and that the S&B had less effective seals...the Russian steel cased in some calibers has a similar red sealant. Most of the 7.62x39 and 9x18 that I have has it. Not sure of it's effectiveness....I suspect that it might be pseudo military but have no proof.

Maybe I'll do a dunk test :) but don't really want to sacrifice any rounds the way things are and might get worse.
 
As for the military, all the crimps and sealant are there for a reason.

Beltfed ammo gets vibrated a lot, besides being bounced around, they don't want the bullets coming loose or the primers.

Then think about what soldiers go through, mud, water, sweat... you name it. When they pull the trigger, they want the ammo to go off.

Do reloaders need to use it? Probably not but depending on how you store it and use it, that would dictate its use on your ammo.
 
A water drop won't kill a primer. Neither will oil.
"...for what reason?..." The military tends to go places where there might be a great deal of wet. Military ammo is sealed to keep it reliable in all conditions. Which is oddly enough the same reason ammo cans are waterproof. Very few of us require that.
Nail polish is very similar to acrylic paint. It's plastic.
 
A drop of water doesn't normally kill a primer, but as I described in the first post, it has happened. The fellow it happened to is a former Aberdeen Proving Grounds Small Arms Test Director and Incident Investigator, so he won't be wrong about what caused it. He will have inspected it closely. To restate what I said, it is not so likely to be an issue if the case and primer are new. I believe this case was well-worn.

The military sealant in all the Lake City ammo I've pulled was pitch (asphaltum, tar). The necks were sized to let the bullet slide in by finger pressure. The pitch is then painted on the inside of the neck and allowed to harden. The case is then charged and the bullet seated to press against that pitch. It makes a pretty good seal.
 
Unclenick said:
The military sealant in all the Lake City ammo I've pulled was pitch (asphaltum, tar). The necks were sized to let the bullet slide in by finger pressure. The pitch is then painted on the inside of the neck and allowed to harden. The case is then charged and the bullet seated to press against that pitch. It makes a pretty good seal.
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That asphaltum sealant in 7.62 NATO M118 match ammo holds the bullet in place when the primer fires and there's no powder in the case. Peak pressure is less than 400 psi.
 
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I've had ammo go bad from water twice. .40 Blazer aluminum and 9mm Mag Tech ball (neither had factory sealant). In both cases the ammo sat wet for extended periods of time. The 9mm ammo sat wet for so long that the cardboard started turning black before I found them.
Some fired normally, some had dead primers, some fired weakly. After a couple weak ones I threw the rest away.
I only seal primers on some magnum revolver ammo, never on practice ammo.
 
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