I made this almost two years ago, but it's still cool

This place is pretty much dead, so I figured why not post it. A college I'm applying to wanted to see it run, so there it is, up on Youtube. What do you guys think?

My +bow firing

A college I'm applying to actually asked to see one of my Nerf blasters fire. Since it was on Youtube anyway, I figure why not post it, right?

Added a picture to show exactly where I cut, but I would not advise actually cutting it. Without cutting it, you can still just pull the plungerhead back past the catch ring and to the o-ring wall, but I would not suggest this as I noticed wear on my o-ring after doing this. Eventually though I'll get around to modifying the plungerhead to allow more draw. Also, I have noticed decently better performance from both barrels after simply applying teflon tape to the plungerhead, so I guess it just has a S**Tty seal stock.

Man I want one of these haha.

Yeah, this, the SharpFire, and the new SnapFire are essentially giant Jolts, with the SharpFire also having a different priming mech. And the camera is a 14megapixel Olympus Stylus 5010, so the pictures are huge when you click on them, but I still need to find somewhere with decent lighting.

This is essentially a larger jolt, right? I love you picture quality, it's incredible. What kind of camera do you use?

Saw the DoubleDown for the first time awhile back and decided I needed what was essentially Nerf's answer to the SNAP

So I bought one.

It's a little bigger than I thought it would be, but my hands still manage to make it look tiny.


First things first, take the 6 screws out of the left side of the handle


Then, pry the left side of the handle off, take a moment to appreciate the simple catch system

then separate the handle from the body of the blaster, leaving you with this

Quick note here, the very front of the barrels comes off with a single screw, but it doesn't do anything useful


Continuing on, remove the 4 screws from the rear of the plungertube and remove the plunger assembly from the plungertube


Take a moment to familiarize yourself with the plungerhead.

Inside the plungerhead is a square recess where the plungerrod sits when screwed on via the screw in the front of the plungerhead.

What I ended up cutting out of the catch ring, although you can actually skip this and still be able to use the o-ring wall as a catch, just hold the trigger down longer to shoot well.

Teflon tape under the o-ring for a better seal.

How my plunger cap looks cut down.
For this first part of the mod, which I'm still working on getting decent pictures of since my camera died partway through, I cut down the 2 prongs on the end cap seen in the pictures above. This allows the plungerhead to be pulled farther back and giving us longer draw. This is actually unnecessary, but I also cut the bottom of the catch ring on the plungerhead down so that it won't catch until the back ridge that holds the o-ring, but you can actually pull it back all the way without cutting down anything. Using the original catch notch, I get about 1.5" of draw; using the farther notch, I'm getting about 2.25" of draw Not a huge increase, and not much of a performance boost stock, but with a stronger spring and new barrels that .75" increase will be quite handy.

Now, this will be a multi-part guide as I'm currently swamped with school work and actual work, and I don't have many of my tools here, but I'll work with what I got at the pace that I can. I do plan on going as far as I can with the DoubleDown, and I figure a single topic that I continue to add to is better than several post, so I'll just edit this whenever I do something new to it.

DoubleDown Facts

Uses a "smart AR" system, firing the right barrel first then the left
Tested with a single dart in alternate barrels, the right barrel shoots harder
The handle is actually pretty comfy for me, even though it's small, and I can see it perhaps used as a springer homemade handle for those who don't want 3D printed
The barrel end, while being essentially useless, could be useful for a barrel space/breach "handle" for longer barrels or a possible airgun conversion(thinking about it)
The pull handle on the plungerrod is a good deal sturdier than the NiteFinder, which is the only similar handle I know of.
Seeing as there isn't much holding the body of the blaster to the handle, reinforcement seems like a must for stronger springs.


If you have suggestions for mods to this, feel free to comment.

Edit: More pics of the plungerhead

Take a SledgeFire, replace lack-luster internals with an airtank, improve the "breach" seal via craft foam or other squishy material, glue PETG barrels that are as long as the outer barrel into several of the shells, have a triple shot breach loader with backup shells. I've actually never used PETG for barrels before seeing as CPVC was always easier and cheaper to come by, as well as being pretty sturdy, so this will be my first venture with it. Depending on whether or not the outer barrel is bigger around than the shells, I might also consider a spacer for the barrels that will fit in the outer barrel. I figure, the SledgeFire is a really nice shell, and the breach loading reminds me of the DoubleShot, so I'll make it useful.

Ok, so you may remember this picture of progress towards my failed masterkey project

Sorry for 5yo blur as F**K, but it's given me an idea. I'm going to attempt to do a tank reinforcement and tank expansion on a BBUMB at the same time. I'll drill holes into the actual tank to allow airflow, then glue a 1.5"x.5" threaded bushing over the front; the .5" section actually fits fairly snugly around the original barrel and valve opening and is threaded for different barrel setups, and the 1.5" part seals against the ridge of the tank as seen in the picture. For the back half, I can again drill some holes for flow, glue some CPVC around the pin, then use a 1.5"x .5" slip bushing with a PVC stub to seal the CPVC and a 1.5" coupler to seal with the front. Using a coupler will give even more support to then tank, and will allow me to space the back bushing away from the tank some if I want to increase the volume more than already. It will also allow me to bolt the rear bushing into the coupler instead of gluing it, meaning I'll be able to remove the bushing in case the string to the pin breaks or there are other issues. Seeing as the front part of the valve on the tank I'll be using has already been cut down(damnit past-me), there's a really good chance I'll end up with the pin misaligning often, especially with a string instead of the trigger pin and lever. I figure this'll end up with somewhat-similar performance to my EPVAT, but with less effort on the seal. It could also be done to a new BBUMB since the shells are nice and spacey. I'd actually really like to shove something like this in a Thunderblast when it comes out for awesome rocket-shooting.

 Yeah, it's really annoying going through old threads looking for information and they're all like "Look at image for details" *image link is dead*. Anyway, there's also a way to embed entire Imgur albums, so I'm gonna look into figuring out how to get them to post here.