"sealing" ammo from moisture

[D.B. Cooper]

I seem to recall reading someplace that one can put paint (Testor's Model Paint, fingernail polish, I don't know what specifically) inside a primer pocket before seating the primer and then put paint around the base of the projectile (or perhaps inside the case mouth) before seating the projectile, and that will essentially waterproof (or at least moistureproof) reloaded centerfire ammo.

Is any of this true, or is it internet fantasyland?

Are there other ways to seal moisture out of ammo for long term storage/ (besides vacuum sealing)?

 

[ColtPythonElite]

Never saw the need...They are pretty darn sealed as is.

I have ran quite a few rounds through the washer by accident. Never had one fail to fire.

 

[SamT1]

Everything I’ve run through the washer has shot!
Steel Ammo can with a desiccant pack in it is the king. Plastic ones are OK if your not going to touch them, they flex when you move them and break the seal.

 

[LoneGoose]

I know of an off-the-shelf sealant that comes in a little bottle like nail polish. The instructions say to apply it to the loaded cartridge at the seam between primer and base, and the seam where the bullet joins the case mouth. I figured it will wick into any voids.

 

[FROGO207]

The ones I seal I use some thinned out model paint and a tooth pick. Just run the dipped toothpick around the primer and the bullet brass junction, let it set a few seconds and wipe the excess off It seals plenty good. It does have to be thin enough to go into the gap however. But I usually do not bother do it to my ammo these days as I am not storing it up.

 

[Col. Harrumph]

I've used Testors model enamel around the seated primer but never actually tested for effectiveness. Our rich uncle used to (and still does for all I know) seal inside the case mouth with some sort of asphalt concoction.

 

[illinoisburt]

Primer sealant only goes on after the primer is seated. Basically forms a ring. There are commercial sealants, but any thin lacquer works fine including model paint and nail polish. A little goes a long, long way. Can do the same with the bullet. Honestly its probably not important except where rounds might be submerged at depth for long time periods. There have been a lot of ad hoc experiments (including some on THR) that sat standard reloads in water for months without any moisture intrusion. The pressed fit of soft metals used in ammo tends to make a good seal + shelf life of modern ammunition is long (as in decades) with minimal care.

 

[homatok]

I use nail polish to color-code for different loads. It may also provide a water-tight seal, I don't really know. All I do is, once the rounds are loaded, I dab on a bit of polish, wait a second or two and lightly swipe the base over a piece of shop towel. The towel catches excess polish and leaves a bright ring of color around the primer.

 

[Blue68f100]

Not really necessary unless your planing on storing it under water. The friction fit between the brass, primer and bullet should provide a sufficient seal if you happen to go for a swim or run them through the washing machine. I use the military ammo cans for all my storage.

 

[RecoilRob]

I loaded a bunch of 38's for a friend in Florida to use in his 'bang-stick' while scuba diving. The normal 38's didn't impress him but the reloads I made were quite a bit hotter and he liked how they performed. Sealed them with fingernail polish and he had no problems at the normal scuba depths.

 

[Hondo 60]

Never saw the need...They are pretty darn sealed as is.

I have ran quite a few rounds through the washer by accident. Never had one fail to fire.

Yup same here.
Ran the same round thru the washing machine 4 times.
It fired just like all the other "unwashed masses" (pun intended)

 

[jmorris]

One engineer I knew always said you can’t seal water out, only in.

I have had rounds left in clothing go through the wash cycle and still fire, I don’t do anything special to them.

For bulk I think it would be hard to beat vacuum sealing. Other than that, an air tight container with some hygroscopic substance in it like desiccant packs, to suck up what moisture you close in there with the rounds.

 

[blarby]

Primer sealant is actually commercially available from Hornady, but is only half the battle. ( it works, btw...but any waterproof shellac would) I use it on my waterfowl shotshell loads, and it looks megapro compared to all the other guys reloads on the goose line . Comes 4 to a pack in a handy applicator that looks like superglue.

If you want to waterproof case mouths, military armories coat the bullet shank and base in Slicktar before seating, and it air cures to a waterproof seal. Thats the black stuff on all of your milspec pulldowns.

Ironically, if you seat cast, wax lubed bullets, you've already done the front half as good as any.

 

[243winxb]

Waterproof Ammo

PRIMER SEALANT: Water resistant lacquer is used by Federal on XM193 & case mouth sealant is also used . http://www.mlefiaa.org/files/ERPR/XM193.pdf Lake City Army Ammunition is also tested for waterproofing. http://www.army.mil/article/11859 If your going into the water, do seal the ammo. I dont. For long term storage, there are other things to worry about. Some powders have special additives for long term storage.

Asphalt, water based ammunition waterproofing sealant

http://www.hernon.com/search-for-adhesives/522/Hernon® Bullet Proof 650Note that Federal lists bullet pull at a minimum of 35 lbs with a sealant .
The sealant is to water proof, but may increase bullet pull? I would guess, cold weld of bullet and case may add to the pounds of pull needed to move a bullet?? Would depend on how long the ammo was in storage. Maximum attainable bullet pull is about 100 lbs. without sealants.

 

[Rule3]

I think NatureBoy has color coordinated Nail Polish for different calibers.

 

[hdwhit]

D.B. Cooper asked:
Is any of this true, or is it internet fantasyland?

It is true that there are commercially available sealants for ammunition, but you don't put them in the primer pocket before seating the primers, you use the sealant to paint around the base of the primer AFTER it is seated. As to sealing the bullet, you would "paint" the sealant around the base of the bullet and then seat it.

But, what when you do this, what you are concerned about is NOT waterproofing the cartridge. As ColtPythonElite said in post #2, ammunition is pretty well waterproof as it is. And, tiny amounts of water vapor does not "deactivate" primers of powder. The reason the military seals its ammunition is to prevent incursion of petroleum-based chemicals and solvents that CAN affect powder and primers. Unless you intend to bathe your ammunition in huge amounts of WD-40, you probably don't need to seal it.

I DO "seal" my primers by "painting" fingernail polish across the case head and then wiping off the excess with a paper towel. But this is not done to keep out moisture or solvents. It is done 1) for cosmetic reasons since I use black fingernail polish and think the black ring around the primer looks nice, and 2) to identify unusual rounds/loads. Not too long ago, I bought some primed brass. I mistakenly read the advertisement to say that the brass was new and had been pulled down. As it turned out, it was actually pull-downs of "factory" reloads and was quite disappointing. I "sealed" the primers in this brass with red fingernail polish so that I can readily identify it.