A glock being fired underwater

Can A Glock Fire Underwater? – What Happens When You Fire

Glocks have an almost universal reputation for being reliable. They don’t break, they don’t jam, and they rarely fail when fired. But can they fire underwater? The answer may surprise you.

So, can a Glock fire underwater? Yes! They can. Glocks can fire underwater relatively easily given the circumstances. So long as the rounds are intact they will still fire. Glocks have internal firing systems, not hammers, and this works to their advantage. While Glocks can fire underwater, you may struggle to hit your target with any meaningful accuracy. 

This short article will answer any questions you may have had about Glocks, and pistols in general, firing underwater.

Can A Glock Fire Underwater?

Glocks can fire underwater. The reason being is that they are very cleverly designed to have all of their firing mechanisms inside the gun itself. The firing mechanism is entirely internal, compared to say the Beretta 92 which relies on a hammer. 

This works in two ways. First, the hammer and pin are exposed the round to the water far more than keeping the firing mechanism internal. Water dampens the explosive power of each round meaning if it does fire (it often won’t) it won’t go very far at all. 

Additionally, the hammer moving through water will go far slower than through air. Water is far denser than air and offers far more resistance. If you imagine yourself in a swimming pool, think of quickly you can move your arm when it is entirely submerged underwater. Compare that to how fast you can swing it when it’s out of the water. The difference is ginormous. This is why you may not even get enough power in the hammer to fire the round.

Because Glock is so dependent on their reputation for making reliable firearms, they regularly test their weapons under extreme stresses and intentional neglect. Glocks can be thrown off buildings, ran over by cars, buried in the sand, and submerged in water. 

Glock have designed their weapons so that they can not only be submerged underwater but be frozen entirely. Even when frozen solid the Glock will continue to fire as normal, once it has thawed of course. Glocks are regularly used in the military and the police force. In the military especially, firing your gun when wet or even submerged entirely can be a necessity. 

It can be the difference between life and death. In Vietnam those whose guns failed to fire when wet/submerged died. This is a gross oversimplification but you get the idea of how important a weapon’s reliability in these conditions is. 

Another more specific example is Normandy in world war 2. When soldiers landed at the beaches by sea they were forced to fight and claw their way up the beachhead. Many of the men who took part in this operation never made it to the beach by boat, they ended up swimming. With their weapon. Many sadly arrived at the beach with a malfunctioning gun due to water damage. Their odds were sadly not good.

The Physics Of A Gun Firing Underwater

The simple explanation of how a gun fires underwater are the same as above water. The hammer hits the pin, the pin and gunpowder propel the bullet forward. The difference is underwater there are more factors to consider. As mentioned above, being underwater can cause problems with the hammer and the bullet firing. 

Even when they work as planned, there are complications. Water is approximately 1000 times denser than air. The resistance the bullet faces before it even leaves the barrel is tremendous. This is why guns are wildly inaccurate underwater. 

Unless you have a rifled barrel, chances are you wouldn’t be able to hit a standard target from more than 5 feet away. You would be lucky to even get it on the board, let alone hit your mark.

This works both ways. When you fire a bullet at someone underwater, even if you aren’t yourself, you are unlikely to hit them. The deeper they are the harder it will be. If someone were to sit on the bottom of a 20-foot deep swimming pool and you were to try and shoot them you wouldn’t hit them. 

You could empty an entire clip trying to hit them and they would likely be entirely fine. Interestingly, even if you did hit them the chances of it injuring them would be minuscule. Bullets from a standard pistol lose their lethality after about 8 feet. 

At 20 feet it would feel more like someone threw a pebble at you. Don’t try this at home, it very well may be safe but it’s not worth the risk. Don’ play games with guns. The theory alone should be enough to satisfy you here for your safety and those around you.

Something else to consider is the chemical reaction that takes place when a bullet is fired. It isn’t a complex one, the gunpowder ignites and expels the bullet out of the barrel. This is a simple process to understand at its core. 

Explosions require three things. They need something flammable. They need something to trigger the explosion, be it heat or pressure. And they need oxygen. Fires use oxygen for fuel, even if (like in the case of a bullet) it only needs a tiny amount. There is less oxygen underwater (but not zero). So the explosion of the round will be stunted.

How Far Will A 9mm Travel When Fired Underwater?

As mentioned above, a 9mm will only travel for a few feet with lethality. After 20 feet you likely couldn’t hit a car. Even if you did, you wouldn’t see any sign of impact. When it comes to the actual distance a bullet can travel is almost infinity, depending upon the depth of the water.

A bullet fired in a swimming pool will travel forwards, and then downwards, until it hits the bottom of the pool. A bullet fired in the ocean will eventually travel to the ocean floor. In theory, if you had an endless body of water the bullet would fall perpetually downwards. Bullets are denser than water, so they would sink.


Glocks are very sturdy, very reliable, and very safe. Glock has performed numerous tests on their weapons, as have independent investigators, they all agree that not only can a Glock fire when wet it can fire underwater. 

It may not do any damage, but it will fire. It isn’t a good idea to keep the weapon submerged for long periods as the bullets may become damp. The problem here lies with the ammunition, not the gun itself. 

Leave a Comment