Vacuum Sealing Ammo | Is It a Good Idea?


Vacuum sealing ammunition is a method of storing ammo in a container without air or moisture. This helps to prevent oxidation and any moisture from seeping into your ammunition or rounds. But is it a good idea?

Vacuum sealing ammo is a good idea. It ensures your ammunition is safe from the elements, preventing corrosion. Because of that, it keeps ammo and firearms in the best conditions for use for a long time.

Read on for more details on why you should vacuum seal ammo, the downsides of doing it, and helpful tips to do it better.

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Does Vacuum Sealing Ammo Work?

Vacuum sealing ammo works. Notably, the absence of air, moisture, and oxygen from the container prevents oxidation and condensation. Without any air for bacteria growth, your ammunition should last longer than if you stored it in a non-airtight container.

  • Oxidation: While oxidation doesn’t directly affect firing, it corrodes and rusts metals when in contact. A bullet that has been exposed to air is more likely to have a damaged coating or have oxidized inside the casing, making each piece less reliable than new ammo.
  • Condensation: When your ammunition comes into contact with humidity, condensation forms inside the container and on the ammunition. This moisture can be corrosive and damage your ammo or affect its position within the container.

The Verdict

Vacuum sealing ammo is a relatively simple process with a large payoff in the long-term storage of ammunition.

Ammo that has been vacuum-sealed will have no air to react with inside the container, eliminating oxidation and condensation. It may be worth trying out the process if you have some ammunition that isn’t currently being stored properly.

This video shows what vacuum-sealed ammo looks like:

Why You Should Vacuum Seal Ammo (and the Cons of Doing That)

There are many reasons why you should consider vacuum-sealing your ammunition. These include:

  1. No air: This prevents oxygen from causing oxidation and corrosion, which will damage your ammo over time. This also prevents oxygen from seeping into the cartridge or bullet itself, giving it a much longer shelf-life than stored in another container.
  2. No moisture: The vacuum seal process removes all moisture from inside the airtight bag that holds your ammunition. This eliminates condensation and keeps your ammunition in one place.
  3. Improved durability: Because the moisture and oxygen have been removed from inside the container, your ammo will last much longer than if you stored it in another container or at room temperature with no protection. [Possible exception: Canned Ammo]
  4. Easy storage: Ammunition is bulky and difficult to store, but you can easily pack it into a smaller space by vacuum sealing it. This makes room for more ammunition and reduces the stress on your storage space.

However, that doesn’t mean vacuum sealing ammo doesn’t come with its cons. While it may be worth the effort, there are some negatives to consider before you start. These include:

  1. Time-consuming: Unlike most packaging, this process takes some time to prepare. You’ll need to gather your materials and ensure you have enough vacuum bags for the ammunition you are storing. It’s a pain in the butt and takes time to vacuum seal it correctly. But this is more of an inconvenience than an actual con in my opinion.
  2. Large bags: Because this process requires you to put the ammunition into a large bag instead of its usual container, you may need some decent space. If you’re only storing a few rounds, this may not be the best option for you.
  3. Unopened ammo: If you aren’t planning to open your rounds, this may not be the best choice. Some air will need to circulate for your ammunition to fire correctly – however, most manufacturers leave a small hole in their cartridges that allows oxygen inside.
  4. Sealing Issues: There is some concern whether the vacuum sealant can cause a vacuum and suck in air for flaring or other issues. You should open and close the bags a few times to make sure that it’s sealed correctly.
  5. Might make ammo unattractive: Ammo that you’ve just sealed looks really ugly because it turns purple when exposed to oxygen.

Mythbusting a “con”: Some people say that vacuum sealing damages the brass casing by causing it to rust in storage. This is a myth: there is no proof that the sealant used in vacuum sealing causes any damage to casings. You should store the ammo in a cool, dry area. This is true for any method of ammo storage.

Vacuum Sealing Ammo for Long-Term Storage

Arguably, the main reason most gun owners vacuum seal their ammo is to ensure they last the longest time possible.

It would be expensive to keep replacing your ammo frequently due to poor storage. This isn’t only inconvenient but also expensive.

Because of that, it would help to ensure your ammo is free from any elements that may corrode or rust their parts.

How to Vacuum Seal Ammunition

  1. Clean the casings.
  2. Cut the bag to fit around the casing (if necessary) and place it in a sealable plastic bag, then seal.
  3. Insert the casings into the vacuum-sealed bag and massage them around with a little bit of force.
  4. Seal with the sealer.
  5. Store in a cool, dry area until needed (minimum of 6 months).
  6. Apply a thin layer of anti-corrosion grease on the inside of each brass casing before you vacuum seal it. You can do this by wiping with a paper towel or damp cloth or squirting the grease on with an oil-less can of bee’s wax spray (my favorite is made by Melvac).
  7. Apply the vacuum sealer to the end of each cartridge and seal as instructed. Be sure to close all ports on the side of the vacuum pump and tighten the valve after it has been sealed.
  8. Vacuum seal bags should be stored in a cool, dark place or a refrigerator so that they do not develop any room temperature condensation inside of your container.

How Long Will Vacuum Sealed Ammo Last?

In general, if you have a good seal and haven’t shot the ammo recently, it should be fine to go for a very long time.

Most ammunition lasts over ten years if vacuum sealed and left in a cool, dry place with little temperature fluctuation. This will maintain the integrity of your container and ensure that it doesn’t open or start to leak before you have a chance to use the ammunition.

Long-term moisture can affect the position of your ammunition within the container.

In contrast, suppose you remove all of the air from inside a cartridge or bullet. In that case, it won’t oxidize and rust when exposed to oxygen. This makes it nearly impervious to corrosion and damage from long-term storage.

Maintaining your vacuum-sealed ammo

Important things to do:

  1. Make sure that the seal is good before you place ammo into the bag. Open up the zip lock seal and close it again, then open and close it a few more times just make sure there will not be any issues with sealing later on.
  2. After you vacuum your ammo, you’ll see that an ugly purple color appears (click here for reference). Leave the bag open to air for a few hours, or place it outside in the sun to remove the purple coloring.
  3. Rotate your ammo bags every six months, especially if you live in a warmer climate.
  4. Store your ammo in a cool, dry place (a basement is ideal) and it should last indefinitely.

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Tips for Vacuum Sealing Ammunition

Now that you know the pros and cons of vacuum sealing your ammunition, here are some things to keep in mind to make sure that you get the best results when you do it.

Only Use High-Quality, Heavy-Duty Seal Bags

As a rule of thumb, you should use the best quality vacuum seal bags, on the market, like these. The cheaper varieties can easily rip open if you don’t hold them closed while sealing them.

This will result in your ammunition being exposed to oxygen again and may allow moisture into your bag.

For added protection, you may choose to use multiple bags within the same container.

Pro Tip: If you’re unsure of which seal bags to buy, I recommend trying out this brand, found on Amazon. They’re reusable, resizable, and durable, making them an excellent pick for anyone looking for long-term ammo sealing.  

Be Careful When Removing Ammunition From Containers

You don’t want to cut or tear your vacuum seal bag. Doing this will expose your ammunition again and make it susceptible to damage.

When removing rounds from any grenade-style canister, be very gentle. Be sure that you’re holding the ammunition, so it doesn’t fall out of your hands and cause damage.

When opening military-style ammunition cans, you’ll need to use caution not to cut your bag or remove the lid at an angle–this can cause the lid’s edge to tear through your seal.

Solve Ammo Container Sizes Before Vacuum Sealing

Ensure that your ammunition fits inside its storage container before you start the vacuum sealing process, or you’ll need to invest in a larger container before you can finish.

This is especially important if you are storing your ammunition in a smaller container like a waterproof pack or pouch, as it’ll be more difficult to find larger containers for the ammo you need.

Can You Vacuum Seal Primers?

Vacuum sealing primers is not as difficult of a process as vacuum sealing ammo, however it is more time-consuming.

There are different sizes on the market that you can buy that will attach to your vac pump with a hose. You should make sure that all air from the primer has been removed from the container before you seal it.

It’s important to note that if your primer is exposed to too much heat or moisture, there are certain chemicals in some primers that will break down. These chemicals react with the powder used in ammo and can cause corrosion, cracking, and rusting of the ammunition stock over time.

To avoid this, it is recommended that you store your primers in a cool, dry place, possibly even in Mylar bags or individually vacuumed sealed bags. You should also check the primer compartment of your ammo cans regularly to make sure that your primers are not being exposed to moisture or heat.

There are other options for storing primers as well such as using desiccant packets. These will keep the humidity out of the storage area so moisture doesn’t build up and get into your primers. This will allow you to store them longer without worrying about corrosion on any of your ammunition’s parts.

Can You Vacuum Seal Shotgun Shells?

You do not have to vacuum seal shotgun shells because they are not made of metal and the ammo shells are not as heavily affected by moisture exposure. While it is possible to do so, we find that it is not necessary because shotgun shells are made of paper in most cases.

The temperature of the air inside the shotgun shell will be the same as the rest of the room due to its hollow shell, so you won’t have to worry about it being exposed to heat or moisture.

The main reason why people try to vacuum seal their ammo is because they want it to last longer without any unnecessary degradation or rusting of their ammunition’s parts over time.

In order to make sure that this happens, you should make sure that the storage area is sealed up and free from excess moisture.  If you are using a plastic container, then it is best to store it in a cool, dry place.

While shotgun shells are not as likely to corrode or rust as some other types of ammunition, they can be affected by moisture too. This can happen over long periods of time if they aren’t stored properly.

If your ammo is exposed to moisture for an extended period of time, you may notice signs of corrosion on the inside of the shotgun shell that will eventually cause cracking.

How to Store Shotgun Shells

As with all ammunition, it is recommended to store shotgun shells in a cool, dry place. You should also consider using a desiccant packet or Mylar bag to minimize moisture buildup inside the ammo container.

The temperature of the air inside your ammo container should not be warmer than that of the temperature inside your house. This is one of those instances where I wouldn’t recommend using plastic because it can be affected by moisture and heat retention.

You may have noticed that some people use cardboard boxes to store their ammo in instead of zip lock bags. This is not recommended because cardboard absorbs moisture and creates more heat between different items placed inside them, especially if they are stacked on top of each other.

How to Vacuum Seal Rifle Rounds

Vacuum sealing rifle rounds is the same process as vacuum sealing shotgun shells.

Unlike shotgun shells, rifle ammunition is made of different metals and therefore will corrode and rust over time if it is exposed to moisture too long.

In order for these types of ammunition to last a long time, they must be stored in a cool/dry environment that has minimal exposure to heat and moisture. If you are using a plastic container, then it is best to store them in a cool, dry place so that your ammo will not be affected by heat retention.

Can You Vacuum Seal Guns?

You can vacuum seal your guns, but you’ll need to make sure that they’re in a completely non-functional state before doing that. Notably, you’ll need to remove the barrel from your firearm. This helps prevent an accident or injury while you’re preparing your firearm for storage.

Vacuum Sealing Ammo Cans

You really shouldn’t vacuum seal ammunition that’s stored in a metal can.

While it’ll remove the oxygen and condensation, it’ll also cause rust to form on the part of the can’s lid where you cut your bag open to take out the rounds.

This leads to more frequent maintenance for your canned ammo than if you had just not vacuum sealed it.

Final Thoughts

There are several benefits of vacuum sealing ammunition. It can help protect your rounds from damage and keep them dry so that they function properly when needed. Besides, it’s a good idea to avoid the risk of having your ammunition corrode or rust during storage.

As long as you’re careful with how you go about it, you can successfully vacuum-seal your ammunition for long-term storage without causing damage. For the best results, I recommend using quality seal bags or containers. This will ensure that your ammo is ready when you need it most.

I hope this article has been helpful. Thanks for reading!

For more, check out Storing Ammo in Ziplock Bags | Should You Do It?

Jim James

Hey, I'm Jim and the author of this website. I have always been interested in survival, fishing, camping, and anything in nature. In fact, while growing up I spent more time on the water than on land! I am also a best-selling author and have a degree in History, Anthropology, and Music. I hope you find value in the articles on this website. Feel free to contact me if you have any questions or input!

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