Are Nerf guns waterproof?

Nerf gun shells are made using ABS plastic is what which is1.5mm in thickness and are also used in Lego and Duplo blocks.

Although Nerf guns are made of plastic, they are not waterproof since they have internal hardware like springs and screws made from metal that could suffer from rust. Another issue with water going in your gun that could tarnish its plunger, and it would also lose its grease. Also, their overall performance might be affected if they get wet.

A little splash might not hurt, but the darts are made of foams that could also get soggy when wet. 

The most sensitive Nerf guns to water are the flywheel guns, as you need to be sure the breech is entirely closed and shielded from water, including the rain.  

If you have upward facing clamshell seams or a jammed door with holes in it, you would need to use some tape. So with your mags, especially if they have any holes and you also need to cover them.

Making reloads would also be harder since you need to stop water from getting into your mags which are attached to your body. Covering it with plastic would help to ensure its functionality.

How to waterproof your Nerf gun?

If rain is being expected, you could wrap your battery and connector in plastic. There are blaster covers available that would keep your Nerf gun dry. 

Use a Nerf Springer gun instead of a Nerf Flywheel gun as the Nerf Springers would always be more durable in any weather, including a rainy one. 

A high rate of fire control (ROF) flywheel blasters would work well for getting into action that would require a lot of mags and some way of holding them on your person while with Springers, you could just shoot and shoot, and they are slower in the rate of fire control, and reloading might not be needed at all depending on the model thus it’s easier to bring in a rainy day.

Some seasoned Nerfers use electrical tape to cover the whole seam on the top of the blaster, the jam door, holes in the mag well, the area around the rev switch, then the whole battery tray, but if your game would last longer, you could use a springer that doesn’t need batteries. This would be best for light to medium rainfall. If the game is under a heavy downpour, you could tape every other seam or hole in your gun.