Nerf Mods: A Beginner's Guide

Step 6 Understanding Pump Guns

Here, the various mechanisms of pump guns are covered. The example being used in this is the Big Blast. This gun isn't actually made by Nerf, but is made by Buzz Bee Toys. It fires "missiles" and takes as little as five pumps to prime. There are four main parts on pump guns: the pump, pump tube, pressure chamber,and barrel. Shown in Picture 1 is the guns internals, labeled.

In the next picture, the gun's pump can be seen. Like the plunger of a spring gun, it has an O-ring on the front of it. This makes an airtight seal with the pump tube, shown in Picture 2. When pushed forward, the pump compresses the air in the pump tube, and a valve in the pressure chamber lets compressed air into the pressure chamber itself. This pressurizes it. When enough pressure has built up in the pressure chamber, further pumping will only release the air trying to be pumped into the pressure chamber. The object that is responsible for this air-release is called the "over-pressure release valve" and is shown in Picture 3. Additionally, you can see a close up of the pump tube and the pump inside of it in Pictures 4 and 5.

See the metal rod that the trigger is attached to in the next picture? This rod, when pulled back, releases the air in the pressure chamber. The trigger is attached to this rod, so pulling the trigger back will pull the rod back (see next picture), releasing the air in the pressure chamber . The air from the pressure chamber then travels down the barrel and fires the loaded ammo.

Again, if this is unclear, do not be too careful and try to understand everything, opening the gun will help your understanding, and it is unlikely anything will go wrong from simply viewing a gun's internals.

Comments

[MudTalon]

thanks dude if it weren't for this article i wouldn't be considered the 1st class modder i am today

Trust me I'm a doctor

[Zeffary20]

i see how to mod springs and pressurized guns, but how can I mod my Buzz Bee Double Shot?

[MAVREV13]

I modded my big blast and it smokes out of the PVC barrel. I want to say for some help where you cut the barrel will change how it shoots. I'm not trying to be mean I just want to help you geek27 thanks also for the tips they helped me out for a nite finder mod.

[geek27]

Well, the performance of your Big Blast does, after all, depend on how you modified it. Your help is much appreciated, but I do not quite understand the modification you are describing. If you are describing the length of the PVC barrel, yes it will change your results. A shorter barrel will be less accurate, whereas a longer barrel will be more accurate and likely get more range. However, a barrel must not be too long, otherwise the gun might lose some range. As you can see in the picture on the introduction, I actually modified my Big Blast so it has a seven-barrel "shotgun" attachment.

[MAVREV13]

nice mods my internet was down for a long time short story viruses attacked my pc so sorry for takeing forever also nice mod, i love the gun i modded because i had no idea what i was doing at all i used a millitary knife and axe messy but the gun 'smokes' from the barrel and i know it is not smoke but it is cool.

[geek27]

A smoking Big Blast... that's cool!  Some of my homemades have appeared to have "smoked" out of the barrel as well, although I don't exactly know what it is...

Maybe it's vaporized moisture, but that's just a guess...

[MAVREV13]

is is vaporized moisturebut smoke sounds cooler also i have a ? 4 ui was taking apart my big blast when i forgot i puped it up  times and i pulled the triger and it smoked and there as no dart in it

[jeff-o]

Ah, the Big Blast! I modified one of these to shoot foam darts through cardboard. Great fun!