The Importance of Drainage Holes in Military Gun Bags

Keeping a rifle case dry is not just about comfort; it is about protecting a critical tool and staying effective when conditions turn ugly. Over the years I have seen plenty of “tactical” gun bags that look the part but turn into shallow bathtubs the first time they sit in wet grass or ride in the back of a truck during a storm. The difference between a bag that quietly drains and one that traps water often comes down to a few small, easily overlooked details: drainage holes and grommets.

This is the kind of low‑glamour feature seasoned users pay attention to. The fabric, padding, zippers, and coatings all matter, but without a way for intruding water to escape, a gun bag can become a damp, heavy, mildew‑breeding mess. That is why serious tactical backpack and gun‑bag manufacturers repeatedly call out drainage as a deliberate design choice, not an afterthought.

Waterproof, Water-Resistant, and Why Moisture Still Gets In

Before talking about holes in a bag, it helps to be clear on what “waterproof” really means.

AET Tactical explains that truly waterproof packs are engineered as a complete barrier against water, using materials like PVC, TPU, or coated nylon combined with techniques such as heat sealing or high‑frequency welding. In their definition, waterproof gear is built to keep contents dry even in heavy downpours or during brief submersion. Water‑resistant gear is different. It can handle light rain or splashes but will eventually let moisture through, especially under prolonged exposure.

Most soft tactical gun bags sit closer to the water‑resistant side of that spectrum. Leading manufacturers of firearm cases emphasize high‑denier nylon, polyester, and Cordura with polyurethane or TPU coatings, plus features like storm flaps and weather‑resistant bases. Those materials shed a lot of water and shrug off wet ground, but they are not magic. Water can still enter through:

• Long zipper runs that get opened and closed on a rainy range day.
• Stitching channels that are not fully sealed.
• The ends of the bag where padding meets woven fabric.
• Simple user behavior: tossing a bag into wet snow, or setting it down in a puddle while working the line.

Reputable gear makers recognize this reality. AET Tactical specifically mentions drainage holes as one of the additional protection features added to otherwise waterproof packs, on the assumption that under hard use some water will eventually find its way in. LQ Company, which has been building tactical packs and firearm cases since 2009, highlights drainage grommets in both backpack and gun‑bag designs for the same reason: they provide a controlled way for water to get back out.

That is the core point. No matter how good the fabric and coatings are, moisture is a constant in real environments. Moisture management is about barriers and exits, and drainage holes are the exit strategy.

Drainage Holes 101: What They Are and What They Do

Drainage holes, often implemented as metal or reinforced plastic grommets, are small openings typically placed in the lowest areas of a compartment. The bushcraft discussion on drain holes sums up their purpose in simple terms: they let water escape so it does not pool inside and soak or add weight to the contents. Tactical gear makers use almost the same language in their glossaries and product breakdowns.

LQ’s tactical backpack glossary describes drainage holes as a weather and moisture management feature: rain covers and coatings keep most water off, while drainage holes allow any water that does get in to escape from the pack interior, preventing pooling and moisture buildup. In their anatomy guide for durable tactical backpacks, they go further and tie drainage directly to hygiene and performance. They recommend drainage grommets at the bottom panel to let water escape and prevent mildew and unnecessary weight.

For gun bags, the same manufacturer calls out drainage grommets alongside storm flaps and weather‑resistant bases as standard features for professional‑grade firearm cases. The intent is clear. Even though closed‑cell foam and coated fabrics resist absorbing water, any moisture that enters the bag has to go somewhere. Without drainage, it stays trapped around your rifle, magazines, and accessories.

Experienced outdoor users echo this on the civilian side. The bushcraft author behind the “Drain Holes Necessary?” discussion notes that they personally prefer gear with drain holes because in multiple real‑world situations those holes made the difference between quickly shedding water and carrying around a soggy, heavier pouch. They would rather have the option than be stuck with gear that cannot drain at all.

That is the mindset I recommend for military gun bags as well. Drainage holes are not cosmetic; they are a small insurance policy against an inevitable mistake: water finding its way in.

What Drainage Holes Do That Waterproof Fabric Cannot

Waterproof materials and coatings are about reduction. They reduce the rate at which water enters. Drainage holes are about removal. They give water a deliberate path out after it has already infiltrated.

AET Tactical’s breakdown of waterproof tactical backpacks is a good illustration. They do not present drainage holes as a substitute for high‑end materials. Instead, they list them alongside roll‑top closures, external waterproof coatings, and reinforced waterproof bottoms. The assumption is realistic: even if you use TPU or PVC panels, seal the seams with heat, and shield the zipper with a storm flap, rain, spray, or submersion may still push some water inside.

In that situation, a sealed bag without drainage becomes a container. Every step you take sloshes that water across your equipment. In contrast, a bag with drainage lets gravity do its work as soon as you change position, hang the bag vertically, or walk a few hundred yards. The fabrics and padding still protect the contents from direct exposure, but the water has somewhere to exit.

Gun bags share the same physics. Closed‑cell foam padding, which top manufacturers strongly recommend because it does not absorb water, is excellent at keeping impacts away from the firearm. The downside is that any water that gets between the lining and the foam tends to stay there unless you give it a way out. Drainage grommets at the corners or along the lowest edge of the bag are the simplest, most reliable way to get that water moving.

How Military Gun Bags Are Built, and Where Drainage Fits

To understand why drainage holes are important, it helps to look at how quality gun bags are constructed.

LQ Company’s guide to tactical gun bags lays out the typical architecture of a professional‑grade soft case. The outer shell uses durable fabrics such as 1000D or 1680D nylon for maximum abrasion resistance, or 600D to 900D polyester for a balance of toughness, UV resistance, and cost. Cordura nylon appears as a premium option for long‑life duty bags, and ripstop patterns help prevent small tears from spreading.

Those outer fabrics are usually backed by water‑resistant coatings. Polyurethane and TPU coatings add flexible water repellence, while PVC coatings sacrifice some flexibility for higher levels of water resistance. Inside, closed‑cell foam padding protects the firearm from impact and helps the bag retain its shape. In some designs, thermoplastic shields such as Kydex inserts are added in high‑impact zones to approach hard‑case levels of protection around optics or receivers.

Hardware is chosen with similar intent. High‑quality gun bags rely on coil zippers in heavier gauges, often from brands like YKK, with oversized pulls sized for gloved use. Load‑bearing straps use high‑density nylon webbing in wide bands, stitched with bar tacks and reinforced at stress points. Buckles and D‑rings are selected specifically to survive heavy, repeated use under field conditions.

At the base, serious manufacturers add weather‑resistant materials and reinforcements. Rubberized or heavily coated bottom panels resist soak‑through when the bag is placed on wet ground or in a muddy truck bed. Storm flaps over critical closures cut down on direct water entry at the zippers.

Drainage grommets are the quiet partner in this system. They are typically placed in the lowest part of the main weapon compartment and sometimes in secondary pockets that carry magazines or accessories. LQ emphasizes them as part of the moisture management strategy, and the same logic shows up in backpack reviews. Highland Tactical’s Armour pack, for example, uses heavy‑weight polyester that already has solid water resistance, but the reviewer specifically notes drain grommets to let water bleed out of compartments.

The pattern is clear. Professionals who build and test tactical gear treat drainage as a structural feature, not a last‑minute drill hole.

Fabrics, Foam, Coatings, and Their Relationship to Drainage

High‑denier nylon and polyester fabrics, especially when combined with PU, TPU, or PVC coatings, do a good job resisting external moisture. They are tough enough to withstand dragging, rough transport, and the kind of abuse that would shred a typical sporting‑goods bag. Ripstop weaves give you extra insurance against small cuts and punctures.

Closed‑cell foam padding is equally important. It does not soak up water the way open‑cell foam would, which keeps the interior from turning into a heavy sponge. It also maintains its protective characteristics even when exposed to wet environments.

However, these same materials can trap moisture if there is no designed path for that moisture to leave. Coated fabrics and sealed linings prevent water from escaping through the walls of the bag. Closed‑cell foam blocks water penetration, but it also blocks water movement. When water does get in, it tends to sit at the bottom, between layers, or in seams.

Drainage holes work because they acknowledge this reality. The materials form the barrier; the holes relieve the inevitable intrusion.

Seams, Zippers, Bottom Panels, and the Role of Gravity

AET Tactical’s explanation of waterproof construction highlights seams and zippers as critical points. Instead of relying on ordinary stitching, they describe heat sealing or high‑frequency welding to fuse panels, eliminating needle holes that would otherwise leak. They also point out that zippers are common leak points, so waterproof versions often have rubberized coatings and are protected by storm flaps.

Gun bags borrow the same concepts even when they are not aiming for full waterproof ratings. Heavier zipper gauges, fabric shields over the zipper tracks, and careful seam placement are all used to reduce water ingress during normal use. Bottom panels are often doubled with thicker fabric or rubberized layers to resist abrasion and soaking.

From a drainage standpoint, the bottom of the bag is where everything comes together. This is the first area to get wet when you put the bag down on damp ground, and it is also where water will naturally collect inside. LQ’s construction guide for durable tactical backpacks emphasizes that the bottom panel should include drainage grommets precisely to let collected water escape, reduce mildew risk, and avoid carrying unnecessary weight.

Apply that thinking to gun bags and the logic is straightforward. A reinforced, weather‑resistant base keeps water from pushing in from below. Drainage grommets let any internal water, whether from rain, snow, or condensation, find its way out as you move. Gravity, not guesswork, does the work.

Real-World Scenarios Where Drainage Holes Matter

Anyone who trains outdoors, especially with long guns, learns quickly that water has a way of showing up when and where you do not want it. The question is not whether your gun bag will ever get wet but how it behaves when it does.

Outdoor and bushcraft users discuss this in practical terms. The author of the “Drain Holes Necessary?” thread recalls several occasions where drain holes proved beneficial, even in non‑military contexts. Their position is simple: gear with drain holes has saved them enough hassle that they now strongly prefer having the option over going without it.

In a tactical or training context, consider what happens when you:

Set the bag down on wet ground while handling another shooter’s issue. Even with a weather‑resistant base, some moisture can wick up around the sides, and if the zipper is not fully closed, water may enter the compartment itself. With drainage, that water has a way out once you pick the bag up and move.

Throw the bag into a vehicle after a rainy session. Water from your clothing, sling, and other gear may drip into the interior while you are loading out. Without drainage holes, that moisture sits at the bottom of the case during the ride home and the hours before you get around to opening the bag.

Deal with sudden downpours in the field. Many tactical backpacks and gun bags are used by military, law‑enforcement, and security personnel who cannot always wait for ideal weather. As AET Tactical notes, waterproof packs are designed to handle heavy downpours and even brief submersion, but they still include drainage as a fail‑safe when exposure gets extreme.

LQ’s focus on drainage grommets as a defense against mildew and unnecessary weight is not theoretical. A wet bag is heavier, throws off the handling of your kit, and increases the chance that you store a firearm in a damp environment by accident. Over time, that is exactly how rust, mold, and degraded textiles get started.

Weight, Fatigue, and Carry Efficiency

Tactical gear is already heavy. Military‑grade bags and packs are expected to carry serious loads, and the design literature for military packs emphasizes that fabrics, frames, and stitching are chosen to survive thousands of load cycles under demanding weights.

Every bit of trapped water is dead weight with no benefit. While the research notes on bag construction do not attach exact numbers to the weight penalty, manufacturers treat “unnecessary weight” as a serious enough issue that they design specific drainage into the bottom of the pack. Their reasoning applies directly to gun bags that may be carried for long distances during training or operations.

If you are already managing ammunition, armor, and support gear, there is no reason to haul around a pint of water sloshing in the bottom of your rifle case just because the designer skipped grommets.

Moisture, Mildew, and Long-Term Gear Health

LQ’s anatomy guide for durable tactical backpacks explicitly connects poor drainage to mildew, and the same logic holds for gun bags. A damp, closed environment packed with fabric, foam, Velcro, elastic, and rubber is perfect for musty odors and mold growth.

Drainage holes do not replace proper drying and maintenance, but they shorten the exposure window. The faster water leaves, the less time it has to soak into straps, stitching, and linings. That protects not just the firearm but also magazines, slings, optics covers, and any soft accessories stored in the same compartment.

For a value‑driven buyer, this is a simple calculation. A professional‑grade gun bag with proper moisture management can extend the life of everything you store in it. That is worth more than a small cosmetic detail on the outside.

Drainage Holes vs Waterproofing: Complementary, Not Competing

There is a common misconception that if a bag is built from waterproof materials, adding holes somehow “defeats the purpose.” That view ignores how reputable manufacturers actually design wet‑weather gear.

AET Tactical’s overview shows that waterproof packs combine multiple layers of defense: waterproof fabrics, sealed seams, specialized zippers, storm flaps, and in some models, roll‑top closures. Drainage holes are added in recognition that failure is never completely off the table. Zippers get left open a few inches. Packs get tossed into water rather than gently set down. Users are human.

The same is true for gun bags. High‑denier fabrics and coatings reduce the amount of water that gets in. Storm flaps over the main zipper reduce direct exposure from rain and splash. Weather‑resistant bases stop moisture from wicking up from below. Drainage grommets stand ready to remove whatever moisture gets through all of that.

You do not choose between waterproofing and drainage; you choose an intelligent combination of both.

Here is a simple way to visualize the tradeoff.

In practice, the best military gun bags aim for the lower row. They accept that “some water” is unavoidable under hard use and focus on how quickly the bag recovers after exposure.

Downsides and Tradeoffs of Drainage Holes

Drainage holes are not pure upside. They introduce their own considerations, and understanding these is part of buying intelligently.

Any opening in a bag is a potential entry point for something you do not want. While the research notes emphasize water management rather than dust or debris, it is common‑sense that the same grommet that lets droplets out could admit fine particles or insects in certain environments. That is why the bushcraft author’s workaround is so useful. They recommend placing a small piece of tape over the drain hole on the inside of the pouch when you want it effectively closed, while still retaining the hole for drainage when needed.

From a military or law‑enforcement perspective, that translates into flexibility. In extremely wet conditions or when operating around water, you leave the drainage open and accept a little more environmental exchange in return for shedding water quickly. In situations where blowing dust, sand, or other contaminants are a bigger problem than occasional moisture, you can partially close the holes from the inside with tape or similar methods and reopen them later.

The bushcraft writer’s preference is clear: they want gear that has drain holes, even if they are occasionally taped, rather than gear with no drainage at all. That is the practical stance. Options are worth more than a permanently sealed design that fails catastrophically the first time it gets soaked.

Evaluating a Gun Bag’s Drainage in Practice

When you evaluate a military gun bag, do not let coatings and camouflage patterns distract you from the basics. Take a hard look at how the bag will behave after ten minutes in steady rain or a full day on a wet range.

Start with the bottom of the main weapon compartment. Look for visible grommets or reinforced holes along the lowest edge when the bag is carried normally. These are the primary drainage points. On better designs, they are sized and finished so they do not snag on straps or scratch surfaces, but they are large enough that you can see daylight through them.

Next, check whether other compartments that might realistically take on water have their own drainage. Long accessory pockets, magazine sleeves, and external pouches on a rifle case can all collect water. The tactical glossary from LQ emphasizes that drainage holes are meant to allow water to escape from the pack’s interior, not just from a decorative outer layer, so pay attention to whether those holes are placed where the gear actually sits.

Finally, assess the overall moisture management system. Does the bag combine drainage with weather‑resistant bases, storm flaps over zippers, and robust coatings on the fabric, as LQ and other manufacturers recommend? Or is the drainage an afterthought on a bag that will soak through at the first sign of trouble? Drainage holes are most effective when they are part of a coherent design rather than a single drilled grommet on a flimsy shell.

For agencies or businesses ordering in volume, the B2B guidance from experienced manufacturers is blunt: work with suppliers that understand tactical environments, can customize features like drainage layout, and have real quality control over materials and stitching. A bag that carries a department patch but lacks drainage, reinforced bottoms, and proper padding is not saving money; it is shifting costs to weapon maintenance and early replacement.

Field Techniques: Getting the Most from Drainage Holes

Even with a well‑designed gun bag, drainage holes are not a free pass to ignore water. They are a first line of recovery, not the entire recovery plan.

Once you are out of the rain or off the range, treat the bag like any other piece of serious equipment. Open the main compartment fully, orient the bag so that the drainage grommets are at the lowest point, and give it time for water to run out. Shake the bag gently to move trapped droplets toward the exits. If the padding and lining have been exposed to significant moisture, leave the bag unzipped in a dry, ventilated space.

Drainage holes shorten the time it takes to reach a reasonably dry state. They do not replace the need to check your firearm, magazines, and accessories for moisture and wipe or oil them as appropriate for your environment and duty requirements.

When To Prioritize Drainage in Your Buying Decisions

Every buyer has to balance budget, features, and mission profile. Some shooters carry their rifles from apartment to indoor range and back, rarely seeing a wet sidewalk. Others live around rivers, snow, or coastal weather where wet equipment is a weekly fact.

The research on waterproof tactical backpacks points out that high‑quality waterproof packs generally range from about $100 to $300 and that the cost is justified by the protection they provide for electronics and essential gear. Professional‑grade gun bags often live in similar company. If you are already spending at that level for strong materials, padding, and hardware, there is little sense in skipping drainage, especially when multiple experienced manufacturers treat it as a standard feature.

If your bag will see outdoor training, field exercises, or regular duty use, drainage holes are not a luxury. They are one of the quiet indicators that the designer thought about what happens after the product leaves the showroom and gets into real weather.

FAQ

Do drainage holes make my gun bag less waterproof?

Drainage holes change how your bag manages water, but they do not automatically make it “leaky” in the sense that matters. AET Tactical’s definitions help here. Waterproof gear is about forming a barrier against water coming in from outside. Drainage holes are about letting water that is already inside get out.

If the outer shell, seams, and zippers are properly built and protected, the amount of water entering during routine use stays low. Drainage grommets then act as pressure relief when conditions get worse than “routine.” Without them, any water that slips past the coatings and closures would stay trapped. With them, water has a controlled exit path, and the interior dries faster once you are out of the rain.

Can I just tape over drainage holes if I do not want them open?

Yes, and that approach has been suggested directly by experienced users. In the bushcraft discussion on drain holes, the author recommends placing a small piece of tape on the inside of the pouch when you want the hole effectively closed, while still leaving it available for drainage when needed. This gives you the ability to adapt to conditions. In wet environments, you leave the holes open. In situations where you want to limit airflow or fine debris moving through, you can tape them from the inside and remove the tape when circumstances change.

Are drainage holes really necessary if I store my guns dry?

If your gun bag only ever moves between a safe, a clean vehicle, and a dry indoor range, you may go years without noticing the difference. But as soon as you start training outdoors, traveling in bad weather, or operating in environments where water and mud are routine, drainage holes stop being theoretical.

Manufacturers like LQ and AET Tactical, along with reviewers of field‑tested packs such as Highland Tactical’s Armour, do not highlight drainage because it looks good in marketing photos. They highlight it because, across years of real use, it has proven to be a simple, reliable way to keep gear lighter, drier, and less prone to mildew and long‑term moisture problems. From a practical, value‑conscious standpoint, that is exactly the kind of feature you want on a bag that is supposed to protect a critical weapon.

In my experience, the best gear is the gear you do not have to think about when conditions get bad. Drainage holes in a military gun bag are a textbook example. They are cheap, unobtrusive, and easy to overlook, yet when the rain starts or the ground turns to soup, they quietly earn their keep. If you are serious about your rifle and serious about getting full value from the bag that carries it, make sure those small grommets at the bottom are part of the design, not an afterthought.

References

1. https://en.wikipedia.org/wiki/Defensive_fighting_position
2. https://www.wbdg.org/FFC/AF/AFH/afh10_222_v14.pdf
3. https://www.aetgear.com/choosing-hardware-for-your-tactical-backpack-design/
4. https://www.lqcompany.com/anatomy-of-a-durable-tactical-backpack/
5. https://luputacticalgear.com/ultimate-tactical-backpack-glossary/
6. https://szoneier.com/types-of-military-bags/
7. https://aettactical.com/blogs/industry-knowledge/the-truth-about-waterproof-tactical-backpacks?srsltid=AfmBOooY2kgJx4KgviWHQ0V0_A_0n_diVgrAohWmQl3aOa3EHQTCUOBY
8. https://magentobackup.blueforcegear.com/articles/post/dump-pouches-overview-news-post.html
9. https://bushcraftusa.com/threads/drain-holes-necessary.266534/
10. https://apps.dtic.mil/sti/pdfs/ADA592921.pdf