How to Make a Cheap Airsoft Madbull Grenade.




Alright, so this isn't technically a madbull grenade. But it does function similarly, and is much less expensive. This uses a few household items and is very effective, requires no water balloons, firecrackers, or anything specific other than what is required in the instructions section. I have spent almost a year hunting down an effective airsoft grenade. I felt like I was about done when I saw a youtube video on this. Now, I was skeptical at first, but this is the one of the best grenades. Period. So I improved the design, then since I didn't find anything about this on this site, I decided to post it.

P.s. Sorry for the fuzzy pictures. I need a new camera.

Step 1: Getting Your Supplies

So you'll obviously need a few things First of all, you most likely will not have the main part in the grenade. The spring loaded party popper. So go down to party city and buy some. I bought 3 for $3.00. No you may be scared at first when the box says " One time use only" but I assure you. These are very easy to reuse. So now that you have those, you will need:

Duck tape ( Or any tape, Duck tape just looks cool.)

A small screw ( One for each grenade. It is very important you get the right size so try a few different types)

An easter egg. ( Preferably with holes in the top, and I think yellow looks coolest)

Sand Paper. ( I find a rotary tool to be much easier, but you may not have one.)

A pencil.

And of course, Air soft pellets. ( I used .2 grams)

There you have it! you can start building now

Step 2: Preparing the Launcher.

Ok, so first you will need to empty the launcher. You can fire it regularly, if you want, but it makes a mess. I suggest you just fire it into a garbage can and save yourself some time. Now, grab the part on the end that you twisted to fire the launcher. Slowly wiggle it until it pops out. This may take some time, so stay persistent. Eventually, it will come out, and so will the other parts. You should have four parts: The barrel, The hammer, the spring, and the twist trigger. Make sure you peel off the sticker.

Step 3: Sanding Down the Ridges.

This step isn't entirely necessary, but it helps. It makes reloading smother and faster. Take your sand paper or rotary tool and smooth down the ridges on the twist trigger and the inside of the barrel. WARNING: Do not smooth them all the way off, just enough so that the launcher assembly comes out of the barrel more smoothly. There. Now it should be easy to push it in and pull it out. Now to reload the spring.

Step 4: Reloading the Spring Mechanism

All right, now this is the part the manufacturers don't want you to know. You can very easily reload this launcher. So easily, that in mid airsoft combat, it can still be reloaded. This is one of the reasons it has such and advantage on all the other grenades. All you need to do is take the spring, put it onto the twist trigger, put the hammer ( or launcher piece) onto the spring and push down until the small tab sticks out from the slot in the hammer. Then, rotate the hammer until the tab is locked in place. Now this may sound like a lot, but with practice it can be done in a matter of seconds. Insert the finished trigger assembly into the barrel, and twist the trigger. BAM! The impossible is accomplished. You may now reuse your launcher to your hearts content. You can pretty much launch anything that fits in the barrel. But if you want to launch airsoft pellets effectively, keep with this instructable.

Step 5: Airsoft Bb Containment Shell

This is where my original idea comes in. This will allow you to go threw all sorts of terrain, and the bbs will stay in the grenade. Now get your Easter egg, and if you haven't already, split it into two halves. You can use either half, but I think the rounded one looks best. Now, take your pencil and mark a spot near the bottom and drill it with a fairly small drill bit. Then, put the egg half on the barrel and mark where the hole is, as shown in the picture. Drill this hole in the barrel as well. Assembly continued on next step.

Step 6: Airsoft Bb Containment Shell Part 2

Alright now we must secure the egg to the barrel. First, take a small piece of duck tape and tape the egg to the barrel on the OPPOSITE side from the hole you drilled. This will be our hinge. Then, take your small screw and put it through the egg and the barrel, securing the egg to the barrel. Now it is VERY IMPORTANT that you find a screw that can be taken out without too much effort, yet will not just fall out and dump the bbs everywhere. Once that is in place the launcher is ready to be fired!

( If you were paying attention to the Instructable earlier, I suggested you get an eggshell with holes in it. This give you a place to put your screw once you take it out. VERY HELPFUL if you don't want to lose your screw.

Step 7: Loading and Firing Your Grenade

Finally, the moment of truth. Pour your bbs into the barrel. Now, depending on the type of barrel, you may need to put a little circle of cardboard into there barrel before the bbs to prevent any from falling into the spring mechanism. Also, i suggest putting in 15 to 20 bbs. You can essentially cram up to 50 bbs in this thing but you get much better performance with less bbs. So once your bbs are inside the barrel, the screw has been removed, and the egg shell is flipped down, you can turn the trigger. And would you look at that! 20 bbs launched an average of 30 feet! If your lucky, it can fire up to 40-45 feet! And that's about it! Just reload the spring mechanism as shown in the previous steps and fire again. ITS THAT EASY!!

Check out video for test fire. You can see a blur, but you can't see the bbs land.

Step 8: Conclusion

So there you have it. One of the best grenade type launchers on this website. No messy chemicals or water, no loud and possibly illegal fireworks. Now depending on how many poppers you buy, you can have a small army of grenades forming. And with practice, you can reload each one in about 20 seconds. Now for some tips and ticks.


2. Don't fire this with the egg still on. you can see in the picture, its powerful enough to crack the egg.

3. Give it some angle to increase the firing distance.

4. You can use almost anything that fits on the end as a stopper. For example, the cap in the picture.

I hope you have enjoyed this instructables!

NOTE: I have made a new instructable on how to use this launcher in a Nerf battle. CHECK IT OUT!!!

Step 9:



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    133 Discussions

    Big Baneser

    5 years ago

    No the tip must be pointy! Pointy is scary round is not!

    1 reply

    9 years ago on Introduction

    Duck Tape was invented in WW1 For the army to seal ammunition cases. AND IT WAS CALLED DUCK TAPE because it was water proof

    6 replies

    Reply 8 years ago on Introduction

    not originally, as i said it was originally called duck tape because of it's amphibious qualities.


    6 years ago on Introduction

    put a small balloon or some tissue on the end and then the bb`s can fire out., its harder to reload but means you can fire quicker, say someone pops out of nowhere.Thanks


    Reply 7 years ago on Introduction

    I found my poppers at party city. My first suggestion would be to check there.


    7 years ago on Step 7

    so do i have to take the egg off before firing? Please answer

    1 reply

    Reply 7 years ago on Introduction

    YES! If you don't take the egg off, it will crack. You might be able to put tissue paper over the top if you're looking for a faster way to fire it.