I wonder...Vacuum Sealing Ammo

[Mark1964]

I do original box inside ammo cans, with a 2 or 3 desiccant packs (lately, Dry & Dry 30 grams) inside the ammo can.
If I don't have original box, a zip lock with the air pressed out for bulk, a plastic ammo box such as MTM Case-Gards for premium stuff. These also go into ammo cans.

 

[mcb]

Volatiles, like chemicals in powder, will "boil off" faster under vacuum, not slower, dependant on the vapor pressure of the specific material.

Advantages to vacuum sealing ammo is great for mechanisms like oxidation - brass will stay shiny longer.

However, if you are doing it to try and preserve the powder, you are likely shortening the powder life, not extending it.

There may be things in powder that require oxygen to break down, but I'm not aware of any.

There are no volatiles to boil off in gun powder. The primary ingredient of modern smokeless propellent, used in small arms, is nitrocellulose and nitroglycerin (single base is just nitrocellulose, double base includes both). A vacuum will not hurt the material properties of either of these ingredients or primes.

That said vacuum is probably overkill. The best thing you can do for ammo is store it in a cool dry place for the longest shelf life. If needed put desiccant with the ammo to ensure the dry aspect.

 

[alsaqr]

No need to vacuum pack ammunition. Buy some Army ammunition cans. i have ammunition that has been stored in Army ammo cans since WWII. Seldom have a misfire, some was found to be degraded and was destroyed. i have a large quantity of 5.56mm ammunition in Army cans that was manufactured in the 1960s. Stuff looks and shoots like new.

Working on a remediation site at Fort Ord, CA in 1974 we dug up several cans of .30 caliber ammunition with dates between 1911 and 1915. One can had developed a leak. Ammunition in the other cans was in great shape.

 

[corpo]

These guys must have thought there was something to it. I've had this at least 5 or 6 years.

 

[sparkyv]

That would likely cause condensation to get into the can like crazy around here. Humidity is 87% right now, but 100% is not uncommon this time of the year.

Anyway, he quit vacuum sealing ammo and instead he put factory ammo in its original boxes in ammo cans that had rubber sealed lids and he tossed in chunks of dry ice (frozen CO2) to disperse the oxygen as it melted then he closed up the lid for storage.

I can certainly smell organic solvent when I open up a can of powder, but probably a remnant of the processing and not part of the powder combustion.

There are no volatiles to boil off in gun powder.

I have one of these from Federal, but it's sealed in nitrogen, not vacuum.

These guys must have thought there was something to it. I've had this at least 5 or 6 years.

 

[Lo-Profile]

I sure mine in ammo cans with two 4oz desiccant packs in each one. Have some that have been stored over 20 years with no adverse effect.

 

[Tirod]

Ammo cans I have broken open for distribution to the soldier were crated, canned. The can itself had boxes in it with dessicant and packing. Bandoleers and safety pins were common in some cans. They certainly weren't vacuum packed as the lever lock is difficult enough to loosen - it compresses the O ring. After that atmospheric pressure isn't much different as you pull the lid open easily.

If the biggest consumer of ammo in the world isn't vacuum packaging them at the commodity level of manufacture and storage, then it's been determined there is no need. Ammo is stored for 15 - 20 years like that, rotating stocks and in some instances as it's issued for training it becomes obvious certain lots may have misfires. Those get tagged for marksmanship or even sale, rather than combat. I've seen combat packs with a key like opening (Spam) and others with pop tops however if they are vacuum sealed there's been little to no talk about it when someone finds they were compromised - like coffee or peanuts.

Not to say someone can't vac pack their ammo, humidity is the biggest problem. It corrodes cases, can penetrate neck joints and also primers if they weren't lacquered. Ammo cans broken open and repacked aren't always done in low humidity rooms with new dry cardboard, so it's a constant battle with water more than anything. Long term the Army used an earth sheltered bunker with a huge chimney and grates for ventilation - which sometimes gets varmits inside them. For the most part you open the door and stand back as the skunks, snakes, possums, raccoons, rats etc bail out. You just never know what got in there over the last ten or fifteen years.

An individual taking the extra step isnt out too much, a government would spend millions a year, and can't, especially since the cost/benefits aren't that good. Nitrogen is now more commonly available to air up tires, that might be an approach to take - squirt some into the bag or can, seal and done.

 

[Ironicaintit]

I’ve toyed with the idea of treating ammo cans the same way as purging a refrigeration system.
Use a manifold with gauges, pull a vacuum with a pump, then fill it with nitrogen.

I’d only go that far if I planned to bury it in the yard for who knows how long...

the downside to trying to hold a vacuum, is if the seal breaks, it’s pulling in atmosphere.

on the other hand, if it’s filled with an inert gas and the seal breaks, you still have the gas, just the pressure has equalized.

I’m lazy...throw it in a genuine GI can and call it a day.

 

[Pat Riot]

That would likely cause condensation to get into the can like crazy around here. Humidity is 87% right now, but 100% is not uncommon this time of the year.

Yeah, he was doing it in the heat of summer in South Carolina. Humidity was low but temps were over 100. He said he did this when he lived in Utah as well.
I didn’t really consider humidity to be a factor as the CO2 displaces the oxygen.

 

[anothernewb]

I've shot some reloads from 30 years ago that were stored in less than ideal conditions in metal coffee cans that weathered several ND winters and one flood - in a cheap apartment garage with no ill effects. They weren't pretty. some had corrosion on the brass, but they all went bang.

 

[crestoncowboy]

I had never really felt the need to vacuum seal ammo until the great .40 S&W sell off from a few years back. I vacuum sealed several cases of ranger T and HST that I got for 130-170 for 500 rds. Vacuum sealing works great if the ammo is boxed. Not worth a crap if its loose.

A few years back when cci had the rebates on black box loose ammo I tried vacuuming simply to make transporting easier with bad results. Pierced bags. Ammo was fine though.

Years ago I bought several thousand rounds of 45 and 40 Gold dots. The price was 30 ish per 250 rounds. They were loose in vacuum packs that were in a brown box. Labeled police trade in but I believed them to be seconds. The rims (yes i know 45 and 40 Aren't rimmed cartridges but by definition the edge of an object is a rim...) of the cartridges pierced the vacuum bags and none were sealed any longer. I shot them as plinking ammo and had no issues but I never considered vacuuming loose rounds again until those black box sales.

My dad doesn't shoot much. But he does occasionally drag out some of his ww2 era 30 carbine ammo. The only ammo I've felt degraded over time was rimfire.