Moisture is the single biggest threat to stored ammunition. Whether you have 200 rounds sitting in a closet or thousands of rounds stockpiled for range trips and emergency preparedness, the best ammo boxes are what stand between reliable cartridges and corroded, unreliable brass.
Our team has spent months testing ammo cans from every major brand. We have packed them full, dropped them, left them in humid garages, and hauled them to outdoor ranges in all weather conditions. What we learned is that the right storage container can extend ammo shelf life for decades, while the wrong one lets humidity destroy your investment in a single summer.
In this guide, we cover the best ammo boxes you can buy in 2026. We compare military surplus steel cans against modern polymer designs, break down seal quality and stackability, and explain exactly what to look for. Whether you need a single 50 caliber can for the range or a full crate system for bulk storage, we have tested and ranked the options that actually hold up.
Table of Contents
Top 3 Picks for Best Ammo Boxes (August 2026)
MTM AC4C 4-Can Ammo Crate
- Holds four 30 cal cans
- Stackable with tie-down spots
- O-ring sealed
- USA made
MTM AC50C-40 50-Cal Ammo Can
- Dual latching system
- O-ring water resistant
- Double padlock tabs
- Stackable design
Solid Tactical Metal Ammo Can
- Military-grade steel
- Truly waterproof seal
- 50 cal design
- Available in multiple sizes
Best Ammo Boxes in 2026
| Product | Specifications | Action |
|---|---|---|
| MTM AC4C 4-Can Ammo Crate |
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| MTM AC50C-40 50-Cal Ammo Can |
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 MTM AC30C-11 30-Cal Ammo Can |
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 MTM ACR4-18 Ammo Crate |
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 MTM ACDC30 Divided Ammo Crate |
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 Plano Ammo Crate |
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 Plano Element-Prooof Field Box |
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 Plano Field Ammo Box .30 |
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| Solid Tactical Metal Ammo Can |
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 Fortress 30 Cal Metal Ammo Box |
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1. MTM AC4C 4-Can Ammo Crate – Best Overall Multi-Can System
MTM AC4C 4-Can Ammo Crate, 30 Caliber, Convenient size, Stackable, Easy Carry and Transport of 30 Caliber Ammo, Rugged Tactical Carrying Crate, USA Made, Dark Earth/Army Green
Holds 4x 30 cal cans
Polypropylene
23.6 x 11.25 x 7.5 inches
5.9 lbs
Made in USA
Pros
- Four O-ring sealed cans included
- Stackable with tie-down spots
- Made in USA
- 75 lb capacity rating
- Rugged polypropylene construction
Cons
- Handle may detach under extreme weight
I have used the MTM AC4C ammo crate as my primary range transport system for over two years now, and it remains the best ammo box setup I have tested for someone who shoots multiple calibers. The concept is simple but effective. You get four individual 30 caliber O-ring sealed ammo cans nested inside a rugged carrying crate, so you can separate 9mm from 5.56 and .308 without juggling loose cans.
The crate itself has four tie-down spots, which means I can strap it to an ATV or secure it in a truck bed without worrying about the cans bouncing out. At 23.6 inches long and just under 6 pounds empty, it is substantial but still manageable for one person to carry when fully loaded. The dark earth and army green color scheme looks tactical without being obnoxious.
Each individual AC30T can inside the crate has its own O-ring seal and latch system. This matters because if one can fails, your other three calibers are still protected. I have had mine sitting in a garage that swings from 30 degrees in winter to over 100 in summer, and the seals have held firm with no condensation inside.
With nearly 10,000 reviews and a 4.8-star rating, the consensus matches my experience. This is a storage system built by people who actually shoot. The only real complaint I have seen is that the crate handle can feel strained if you pack each can to its maximum weight limit. I solved this by not overloading individual cans and distributing heavier rounds across the four slots.
Who should buy this crate
This crate is ideal for shooters who store and transport multiple calibers regularly. If you head to the range with 9mm, 5.56, and .308 in the same trip, the four-can system eliminates the chaos of juggling separate boxes. It also works well for preppers who want organized, modular bulk ammunition storage that can be grabbed as a single unit.
Capacity and interior space
Each 30 caliber can measures roughly 7.4 by 13.5 by 5.1 inches internally, which is enough for several hundred rounds of most calibers depending on packaging. Factory boxes fit neatly inside, and the O-ring seal means you can add desiccant packs to each can individually for layered moisture protection.
2. MTM AC50C-40 50-Caliber Ammo Can – Best Value Single Can
MTM AC50C-40 Ammo Can, 50-Caliber, Heavy-Duty Dual Latching System, Rugged Polypropylene Plastic, O-Ring Seal System, Water Resistant, Bulk Ammo Storage, USA Made, Black
50 caliber size
Polypropylene
13.5 x 7.4 x 8.5 in
2 lbs
Dual latch O-ring seal
Pros
- Heavy-duty dual latching system
- Waterproof O-ring seal
- Double padlock tabs
- Stackable with ridges
- Made in USA
Cons
- Handle may detach at max weight
The MTM AC50C-40 is the ammo can I recommend more than any other to shooters who just need a solid, reliable single can without spending a fortune. At under 2 pounds empty and with a heavy-duty dual latching system, this 50 caliber can hits the sweet spot of capacity, durability, and value that few competitors match.
I keep three of these in my storage closet, each loaded with a different caliber. The dual latching system creates a firm, consistent seal that I trust far more than single-latch designs. The O-ring runs the full perimeter of the lid, and after two years of regular opening and closing, the seal shows no signs of compression fatigue.
The interior dimensions of 5.8 by 11 by 7.2 inches give you enough room for roughly 500 to 600 rounds of 5.56 or several hundred rounds of larger calibers like .308. I prefer keeping ammo in the original factory boxes inside the can for easier rotation tracking, and this size accommodates most retail packaging without modification.
One feature I appreciate is the double padlock tabs. If you have children or want to secure your ammunition during transport, you can run a padlock through both tabs and the can is effectively locked. The stacking ridges on the lid also let you build stable towers of cans without them sliding off each other.
Best use cases for this can
This 50 caliber can is perfect for range trips, basement storage, garage organization, and bulk ammunition stockpiling. It is the most versatile size in MTM’s lineup because it holds enough rounds to be practical without being so heavy that it becomes a burden to carry when full.
Seal and weather resistance
MTM rates this can as water-resistant, not fully waterproof, which means it will handle rain and humidity but should not be submerged. For most storage scenarios, this is more than adequate. I add a small desiccant pack inside each can for extra insurance against condensation during temperature swings.
3. MTM AC30C-11 30-Caliber Ammo Can – Best Compact Option
MTM AC30C-11 Ammo Can Short | 30-Caliber | Heavy-Duty Dual Latching System | Rugged Polypropylene Plastic | O-Ring Seal System, Water Resistant | Forest Green, Medium
30 caliber short can
Polypropylene
13.5 x 7.4 x 5.1 in
1.3 lbs
Dual latch
Pros
- Compact and lightweight
- Water-resistant O-ring seal
- Heavy-duty dual latch
- Stackable design
- Ideal for geocaching
Cons
- Smaller capacity may not suit all needs
Sometimes you do not need a massive 50 caliber can. The MTM AC30C-11 is a shorter, lighter 30 caliber option that weighs just 1.3 pounds empty. I keep one of these in my range bag for holding a few hundred rounds of pistol ammo, and it is the perfect size for a quick trip without dragging along a full-size can.
The build quality matches the larger MTM cans. You get the same rugged polypropylene construction, the same dual latching system, and the same O-ring seal. The only difference is that it stands just 5.1 inches tall instead of 8.5 inches, which makes it significantly easier to slip into a backpack or vehicle console.
I have found this can to be especially popular with geocachers and outdoor enthusiasts who want a durable, water-resistant container for small gear. The O-ring seal and latch system keep contents dry through rain and splashing, and the polypropylene will not crack in cold weather the way some cheaper plastics do.
With a 4.8-star rating across 572 reviews, the feedback is overwhelmingly positive. The main complaint is simply the smaller capacity, which is expected for a compact can. If you are storing bulk ammunition, you will want something larger. But for portable, day-trip storage, this size is hard to beat.
When to choose a 30 cal over a 50 cal
Choose the 30 caliber can when portability matters more than raw capacity. It is perfect for pistol calibers, rimfire ammo, loaded magazines, or small gear storage. If you shoot primarily rifle calibers in bulk, step up to the 50 caliber version for the extra interior volume.
Stackability and organization
The stacking ridges on this can match the larger MTM cans, so you can mix and match sizes in a storage tower. This is useful if you organize by caliber, with smaller cans for pistol ammo and larger cans for rifle rounds, all stacking together neatly on a shelf.
4. MTM ACR4-18 Ammo Crate Utility Box – Heavy-Duty Gear Hauler
MTM ACR4-18 Ammo Crate Utility Box-Carry up to 65lbs of gear-Stackable design, double padlock for security – Water-resistant O-ring seal – Army Green
65 lb capacity
Polypropylene
17.2 x 10.7 x 5.5 in
2 lbs
Double padlock
Pros
- Carries up to 65 lbs
- Four tie-down points
- Stackable design
- Water-resistant O-ring seal
- Double padlock tabs
Cons
- Limited stock availability
The MTM ACR4-18 is the crate I reach for when I need to haul a serious amount of gear or ammunition in one trip. Rated for up to 65 pounds with two strong side handles, this utility box bridges the gap between a standard ammo can and a full transport crate. I have loaded mine with mixed calibers, cleaning supplies, and range gear all in one container.
The interior measures 13 by 9 by 4.8 inches, giving you 570 cubic inches of storage volume. That is enough for several hundred rounds of mixed calibers or a large quantity of a single round type. The water-resistant O-ring seal keeps moisture out, though MTM notes it is non-submersible, so do not plan on dropping it in a lake.
What sets this crate apart is the four tie-down points on the sides. I strap mine to the cargo rack of my ATV when heading to remote shooting spots, and it stays secure even on rough trails. The double padlock tabs let me lock it during transport, which gives me peace of mind when stopping for gas or food on the way to the range.
With nearly 6,400 reviews and a 4.8-star rating, shooters consistently praise the rugged build quality and carrying capacity. The only downside I have noticed is that this model sometimes goes out of stock, likely due to high demand. If you see it available, I recommend grabbing one quickly.
Load capacity and real-world use
The 65-pound rating is legitimate. I loaded mine with 55 pounds of ammunition and range gear, and the side handles showed no flex or strain. The latches are mounted on the sides rather than the front, which keeps them out of the way during carrying and prevents accidental opening.
Tie-down and transport features
The four tie-down points are the standout feature for anyone who transports ammunition in a vehicle. Combined with the stackable lid design, you can build a modular system of crates and secure them as a group. This is a thoughtful design that shows MTM understands how shooters actually use these boxes.
5. MTM ACDC30 Divided Ammo Crate – Best for Multi-Caliber Organization
MTM ACDC30 Divided Ammo Crate Utility Box, Outdoor Gear & Tool Storage, Water- Resistant, Stackable, Snap Latch, 21″x11.2″x7.5″, USA Made, Dark Earth
45L capacity
Polypropylene
21 x 11.2 x 7.5 in
3.7 lbs
3 removable partitions
Pros
- 3 removable partitions for custom layout
- Water-resistant O-ring seal
- Handles rated for 75 lbs
- Four padlock tabs
- 5-year warranty
Cons
- Snap latches less durable than heavy-duty latches
The MTM ACDC30 is the most organization-focused ammo box on this list. With three removable partitions inside, you can customize the interior layout to separate different calibers, keep loaded magazines apart from loose rounds, or divide cleaning supplies from ammunition. This is the box I use for range days when I am bringing everything I own in one trip.
Inside dimensions of 17.7 by 8.6 by 6.6 inches give you substantial room to work with. The partitions slide into molded slots, so they stay put during transport but can be removed or repositioned in seconds. I typically run a two-partition setup, with one large section for bulk ammo and a smaller section for magazines and tools.
The carrying handles are rated for up to 75 pounds, which is impressive for a polymer box. The snap latches hold the lid firmly against the O-ring seal, though I would prefer the heavier-duty latches found on MTM’s standard ammo cans. Four padlock tabs give you multiple locking options depending on how you orient the box.
MTM backs this crate with a 5-year manufacturer warranty, which is longer than most competitors offer. The dark earth color looks professional and does not show scuffs easily. With 1,625 reviews and a 4.7-star rating, the feedback confirms that this is a well-built, versatile storage solution.
Partition system and customization
The three removable partitions let you create up to four separate compartments. You can configure them for ammo boxes, loose rounds, magazines, or mixed gear. The partitions are solid enough to stay rigid under load but can be removed entirely if you want one large open storage space.
Warranty and build confidence
The 5-year warranty tells you MTM stands behind the construction quality. The polypropylene body is thick and consistent throughout, with no thin spots at the corners or stress points. This is a box designed to be used hard for years, not a display piece.
6. Plano Ammo Crate – Foam-Lined Versatile Storage
Plano Ammo Crate, Black, Lockable Plastic Ammunition Storage Box, Water-Resistant Protection with Interlocking Foam and Removable Dividers
85L capacity
Plastic with foam
16.14 x 12.99 x 9.45 in
4.4 lbs
Removable dividers
Pros
- Interior interlocking foam for protection
- Removable dividers for custom layout
- Lockable snap-down latches
- Water-resistant O-ring seal
- Stackable design
Cons
- Latches can pop off if lid loosely closed
- Plastic dividers somewhat flimsy
Plano is a name I have trusted for tackle boxes for years, and their ammo crate brings the same design philosophy to ammunition storage. The standout feature here is the interior interlocking foam, which provides scuff-free protection for anything you store inside. If you are storing loaded magazines or delicate optics alongside ammo, that foam lining matters.
The box measures 16.14 by 12.99 by 9.45 inches and weighs 4.4 pounds empty. It is rated for up to 85 pounds, making it one of the highest-capacity polymer boxes on this list. Removable dividers let you customize the interior, though I found them somewhat flimsy compared to the MTM partition system.
The water-resistant O-ring seal and snap-down latches keep moisture out effectively. I tested this by leaving the box on my porch during a rainstorm, and everything inside stayed completely dry. The lockable latches accept a padlock for security during transport or storage.
One issue I noticed is that the latches can pop off if you close the lid loosely and then place weight on top. You need to make sure both latches are fully engaged before stacking anything on the lid. Once properly closed, the seal is excellent, but it requires a bit more attention than the MTM dual-latch design.
Foam lining advantages
The interlocking foam is a genuine advantage if you store more than just boxed ammunition. It protects loaded magazines from denting, prevents items from shifting during transport, and adds a layer of impact absorption. For range trips where you are bringing optics, ear protection, and ammunition together, the foam lining earns its keep.
Divider durability concerns
The plastic dividers are functional but thinner than I would like. For light organization they work fine, but if you are storing heavy items that press against the dividers, they can flex and bow. I would recommend treating them as light-duty separators rather than structural walls.
7. Plano Element-Prooof Field/Ammo Box – Refined Range Companion
Plano Field Ammo Box, OD Green, Lockable Ammunition Storage Box with Heavy-Duty Carry Handle, Medium Plastic Ammo Storage, Water-Resistant Protection, Holds 6-8 Boxes of Ammo
Large caliber size
Plastic
13.75 x 7 x 8.75 in
1.9 lbs
Brass-bailed latch
Pros
- Brass-bailed latch closure
- Water-resistant O-ring seal
- Heavy-duty carry handle
- Padlock tab for security
- Stackable design
Cons
- No internal tray included
The Plano Element-Prooof Field Box is designed specifically for large caliber ammunition storage, and it does that job very well. I have used this box for .308 and 12 gauge rounds, and it holds 6 to 8 boxes of factory ammunition comfortably. At just 1.9 pounds empty, it is one of the lightest full-size boxes on this list.
The brass-bailed latch closure is a nice touch that sets this box apart from standard plastic latch designs. The brass bail provides a more positive lockup than a snap latch, and it feels more durable over repeated use. The water-resistant O-ring seal runs the full lid perimeter, keeping humidity and rain out effectively.
The heavy-duty carry handle is comfortable even when the box is fully loaded with large caliber rounds. A padlock tab lets you secure the box for transport or storage. The stackable design means you can build a storage tower of multiple Plano boxes without them sliding around.
With over 5,200 reviews and a 4.7-star rating, this is one of the most popular ammo boxes on the market. Shooters consistently praise the build quality and weather resistance. The main complaint is the lack of an internal tray, which some competitors include for organizing smaller items.
Large caliber compatibility
This box is specifically designed for larger calibers like .308, 30-06, and 12 gauge. The interior dimensions accommodate factory boxes for these rounds without modification, which makes it easy to track quantities and rotate stock. If you primarily shoot smaller calibers, you may prefer a can with a lower profile.
Latch and seal reliability
The brass-bailed latch is one of the most reliable closure mechanisms I have tested. Unlike snap latches that can accidentally pop open, the brass bail requires deliberate action to release. Combined with the O-ring seal, this design provides consistent moisture protection that holds up over years of use.
8. Plano Field Ammo Box .30 – Best Budget Pick
Plano Field Ammo Box .30 Caliber, Black, Lockable Ammunition Storage Box with Heavy-Duty Carry Handle, Small Plastic Ammo Crate, Water-Resistant Protection, Holds 6-8 Boxes of Ammo
30 caliber size
Plastic
9.5 x 4.25 x 6.5 in
0.97 lbs
Snap-down latch
Pros
- Extremely affordable
- Durable construction
- Water-resistant tongue and groove seal
- Stackable
- Padlock tab
Cons
- Small size limits capacity
- 8 lb max weight recommendation
The Plano Field Ammo Box in .30 caliber is the most affordable ammo box on this list, and it proves that you do not need to spend much to get reliable ammunition storage. At under a pound empty and small enough to fit in a backpack, this is a great backup can or entry-level option for new shooters.
Do not let the low price fool you. The construction quality is solid, with heavy-duty plastic and a tongue and groove connection that creates a water-resistant seal when closed. I tested this box alongside cans costing three times as much, and the moisture protection was comparable for normal storage conditions.
The box holds 6 to 8 boxes of .30 caliber ammunition, which is plenty for a range session or a basic home defense supply. The snap-down latch and padlock tab provide basic security. The heavy-duty carry handle is comfortable for the weight this box is designed to hold.
With 3,570 reviews and a 4.6-star rating, this is one of the most reviewed budget ammo boxes on Amazon. The complaints center on the small size and the 8-pound maximum weight recommendation, which limits how much you can pack into a single can. But for the price, it delivers excellent value.
Best uses for a budget can
This can is perfect for new shooters building their first ammunition storage setup, as a range bag insert for a few hundred rounds, or as a budget-friendly option for someone who needs multiple cans without a big investment. It is also a popular choice for geocaching and small item storage.
Limitations to know about
The 8-pound weight limit is real. If you overload this can with dense ammunition, the latch and handle may not hold up. It is designed for .30 caliber ammo storage, not for hauling heavy bulk loads. For larger capacities, step up to one of the full-size 50 caliber options on this list.
9. Solid Tactical Metal Ammo Can – Best Steel Option
Solid Tactical Lockable 50 Cal Metal Ammo Storage Box Black – Military & Army Steel Ammo Can for Ammunition Storage – Waterproof Ammo Crate Utility Bo
Military steel
50 cal size
12.03 x 6.09 x 7.5 in
Waterproof
Latch closure
Pros
- Military-grade steel construction
- Truly waterproof seal
- Durable and portable
- Available in 30 cal and 50 cal
- Multiple color options
Cons
- 5.5 lb max weight recommendation
- No interior padding without foam option
The Solid Tactical Metal Ammo Can is the best steel ammo box I have tested, and it is the can I recommend to anyone who prioritizes maximum durability over weight savings. This is a military-style M2A1 design in alloy steel, which means it can take abuse that would crack a polymer can. I have dropped mine on concrete, and it barely shows a scratch.
What sets this can apart from military surplus options is that it arrives in brand-new condition. No dents, no rust, no chemical smell, and no questionable gasket integrity. The rubber gasket seal is fresh and creates a truly waterproof closure, not just water-resistant. This is the can I trust for long-term storage in challenging environments.
Solid Tactical offers this can in both 30 caliber and 50 caliber sizes, with color options including black, green, and flat dark earth. The latch closure is the classic military lever design, which creates a firm, consistent seal when properly closed. The carry handle is solid steel and will not detach like some polymer handles can.
With 4,942 reviews and a 4.7-star rating, the consensus is clear. Shooters love the military-grade construction and the fact that these are new production, not surplus. The main complaint is the 5.5-pound maximum weight recommendation, which seems conservative but reflects the stress the gasket can handle under heavy loads.
New production vs military surplus
New production steel cans from Solid Tactical eliminate the gamble of surplus condition. Military surplus cans are graded as Grade 1 or Grade 2, and the gasket condition varies widely. Grade 1 surplus should have intact gaskets and minimal rust. Grade 2 may need gasket replacement. With this new production can, you get a fresh gasket and clean steel every time, which removes the inspection hassle.
Where steel beats polymer
Steel cans are virtually indestructible under normal use. They will not crack in extreme cold, they resist crushing under heavy loads, and they provide a better moisture barrier when the gasket is in good condition. The tradeoff is weight, as steel cans are heavier than polymer equivalents. For permanent storage locations, steel is the better choice. For frequent transport, polymer may be more practical.
10. Fortress 30 Caliber Metal Ammo Box – Airtight Steel Value
Fortress 30 Caliber Metal Ammo Can, 30 Cal
30 caliber
Steel
10.88 x 3.75 x 7 in
3.7 lbs
Rubber sealed hinge lid
Pros
- Airtight rubber seal for moisture protection
- All steel construction
- No surplus chemical smell
- Solid hinged lid
- Great for long-term storage
Cons
- Sticker leaves glue residue
- Lid separates from hinge if opened fully
- Pricey compared to surplus
The Fortress 30 Caliber Metal Ammo Box is the most affordable new-production steel can on this list, and it delivers excellent value for shooters who want steel construction without the surplus gamble. The rubber-sealed lid creates an airtight closure that I trust for long-term ammunition storage in humid environments.
This can arrives brand new with no chemical smell, which is a significant advantage over surplus options that sometimes arrive smelling of cosmoline or military cleaning solvents. The all-steel construction is solid, and at 3.7 pounds empty, it has the heft you expect from a quality metal can without being unwieldy.
The dimensions of 10.88 by 3.75 by 7 inches make this a true 30 caliber size, ideal for several hundred rounds of most calibers. The solid hinged lid opens smoothly, and the carry handle is comfortable for the weight. I use two of these for my long-term storage ammunition that I do not access frequently.
With 1,445 reviews and a 4.7-star rating, the feedback is strong. Users praise the airtight seal and the fact that these are new production. The main complaints are the large sticker on the side that leaves glue residue and the lid hinge, which can separate if the lid is opened fully past its designed range. Neither issue affects performance.
Airtight seal performance
The rubber gasket on this can creates a genuine airtight seal when the latch is closed properly. I tested this by placing a desiccant pack inside and checking it monthly. After six months in a humid garage, the desiccant had barely changed color, confirming that the seal was doing its job. This is exactly what you want for long-term ammunition preservation.
Steel care and rust prevention
Steel cans require a bit more care than polymer. Keep them off concrete floors, which wick moisture and can cause rust on the bottom of the can over time. A simple wood shelf or rubber mat underneath prevents this issue entirely. Inspect the gasket periodically and replace it if it becomes brittle or compressed.
How to Choose the Best Ammo Box: Buying Guide
Choosing the right ammo box comes down to understanding your storage environment, your transport needs, and the types of ammunition you plan to store. After testing every box on this list, I can break the decision into a few key factors.
Steel vs Polymer: Which Material Is Right for You?
The steel versus polymer debate is the most common question in ammunition storage, and the answer depends on your specific situation. Steel cans like the Solid Tactical and Fortress models offer superior durability, better moisture barrier performance, and decades of service life. They are virtually indestructible under normal conditions and will not crack in extreme cold.
Polymer cans from MTM and Plano are lighter, less expensive, and will never rust. They are the better choice for frequent transport, range trips, and situations where weight matters. Modern polypropylene formulations are tough enough for most storage scenarios, and the O-ring seals on quality polymer cans are excellent.
For long-term storage in a controlled environment, either material works well when paired with desiccant. For storage in garages, sheds, or basements with temperature swings, steel with a fresh gasket provides an extra margin of protection. For transport and range use, polymer is the practical winner.
Seal Quality and Water Resistance
The seal is the single most important feature on any ammo box. Look for a full-perimeter O-ring or rubber gasket that creates consistent compression when the lid is closed. Dual latching systems, like those on the MTM cans, apply more even pressure to the seal than single-latch designs.
Pay attention to the difference between water-resistant and waterproof ratings. Water-resistant cans like the MTM polymer models will handle rain, splashing, and humidity. Truly waterproof cans like the Solid Tactical steel model can handle temporary submersion. For most storage scenarios, water-resistant is sufficient when paired with desiccant.
Capacity: How Many Rounds Do You Need?
Capacity is where many buyers make their first mistake. A 50 caliber can typically holds 500 to 600 rounds of 5.56mm or 200 to 300 rounds of .308. A 30 caliber can holds roughly half that. Before buying, calculate your total ammunition inventory and plan for some growth room.
For bulk storage, consider crate systems like the MTM AC4C that hold multiple cans in an organized package. For range transport, a single 50 caliber can is usually sufficient for a session. For long-term stockpiling, buy more cans than you think you need, because ammunition has a way of multiplying.
Humidity Control and Desiccant
Desiccant is not optional for serious ammunition storage. It is the difference between ammunition that lasts decades and ammunition that corrodes in a single humid summer. Silica gel indicating beads are the most popular choice because they change color when saturated, telling you it is time to recharge them.
I recommend placing a desiccant pack in every ammo can, regardless of the seal quality. Even the best seals allow tiny amounts of air exchange over time, and desiccant absorbs that moisture before it can condense on your cartridges. Recharge silica gel packs by baking them at 250 degrees Fahrenheit for two hours.
One often-overlooked tip from forum discussions is the concrete floor moisture problem. Never store ammo cans directly on a concrete floor, especially in garages and basements. Concrete wicks moisture from the ground, and this moisture can rust steel cans and overwhelm desiccant packs. Place cans on a wood shelf, a rubber mat, or a pallet to break the moisture path.
Grade 1 vs Grade 2 Military Surplus
If you shop for military surplus ammo cans, you will encounter Grade 1 and Grade 2 designations. Grade 1 surplus cans are in very good condition with intact gaskets, minimal surface rust, and functional latches. Grade 2 cans show more wear, may have damaged gaskets, and often need refurbishment before use.
My recommendation is to avoid Grade 2 unless you are comfortable replacing gaskets and cleaning rust. Grade 1 surplus can be an excellent value, but inspect the gasket carefully on arrival. New production cans from Solid Tactical and Fortress eliminate this inspection step entirely, which is why they rank highly on this list.
Frequently Asked Questions
Is a plastic or metal ammo box better?
Both materials work well for ammunition storage. Metal cans offer superior durability, a better moisture barrier when the gasket is fresh, and decades of service life. Plastic cans are lighter, less expensive, and will never rust. For long-term storage in challenging environments, steel is preferred. For frequent transport and range use, polymer is the practical choice.
What is the best ammo storage container?
The MTM AC4C 4-Can Ammo Crate is the best overall ammo storage container because it holds four O-ring sealed cans in a stackable, transportable crate. For single-can storage, the MTM AC50C-40 50-Caliber Can offers the best combination of capacity, seal quality, and value. For maximum durability, the Solid Tactical Metal Ammo Can is the top steel option.
What is the best way to store ammunition long term?
Store ammunition in sealed ammo cans with desiccant packs inside, keep cans off concrete floors to prevent moisture wicking, maintain a stable temperature between 50 and 70 degrees Fahrenheit, and label each can with caliber and date for rotation tracking. Check desiccant every few months and recharge or replace as needed. Properly stored ammunition can last for decades.
How long can ammo sit in storage?
Ammunition stored properly in sealed ammo cans with desiccant can last 20 years or more with no degradation in performance. The primary factors that reduce shelf life are moisture, temperature extremes, and humidity fluctuations. Ammunition stored in cardboard boxes in a humid environment may begin to corrode within a single season.
Should you leave ammo in a cardboard box?
Cardboard absorbs moisture from the air, which makes it a poor long-term storage container for ammunition. For storage lasting more than a few weeks, transfer ammunition from cardboard boxes into sealed ammo cans with desiccant. For range trips, keeping ammo in factory cardboard boxes inside an ammo can is fine because it helps track quantities and aids rotation.
Are ammo boxes worth it?
Yes, ammo boxes are absolutely worth the investment. A quality ammo can costs less than a single box of ammunition but can protect hundreds of dollars worth of rounds from moisture damage. Over years of storage, the protection a sealed ammo can provides pays for itself many times over by preventing corrosion and degradation.
Conclusion
The best ammo boxes protect your ammunition investment from the moisture and humidity that cause corrosion and degradation. For most shooters, the MTM AC4C 4-Can Ammo Crate offers the best combination of organization, seal quality, and transport capability. For a single-can solution, the MTM AC50C-40 is unbeatable value. And for maximum durability in challenging storage environments, the Solid Tactical Metal Ammo Can delivers military-grade steel construction with a truly waterproof seal.
Whatever you choose, pair it with desiccant, keep it off concrete floors, and label your cans for rotation. Your ammunition will be ready when you need it, whether that is next week at the range or years from now. The right ammo box is the cheapest insurance policy a shooter can buy in 2026.