This is a rainbow-style catch Nerf homemade blaster using 1-inch 200 psi PVC as the plunger tube. It's quite small, but is a lot of fun. Not the easiest build out there, but very far from difficult! Included are options for a single front-loading barrel, a triple forward-facing barrel, and a triple barrel duck's foot (which is hilarious, surprisingly functional, but mayyyyy lack any practical utility). Also included is a six-shot manually-rotated pepperbox front end, which is probably the most useful if you intend to use this as anything but a single-shot backup.

The plunger head, catch, and T-pull should be printed at 100 percent infill.

You will need: 1-inch 200 psi PVC, cut to however long you wish your plunger tube to be. 1/4 inch rod (I used aluminum rod from Ace Hardware) cut to match. A mainspring (I'm using 4 inches of k25) A catchspring (a strong pen spring, or something similar. I got mine at Ace Hardware, can't recall the number. An o-ring (not sure what size I'm using right now, I have a big box and just picked the best fit. Will check and edit later.) 17/32 brass (amount will vary depending on your front end choice) 6-32 screws, two 1 1/4" to hold catch housing in, four 3/8" for the front end, front grip screw, and lower grip panel screw, one 3/4" for the plunger head, and then two 1" for the rear grip screw and upper grip panel screw/trigger pin. Two 6/32 nuts Superglue A drill, hacksaw, and files! And optionally some craft foam, an extra 6-32 1" screw, and another catch spring, if you're building the pepperbox front end.

I've uploaded pictures of the basic trigger/catch mechanism, which is absurdly simple. Building is relatively self-explanatory. For the plunger rod, I just filed a catch notch in around the whole diameter of the rod, using a triangular file. Just have to make sure the back edge of the catch notch is flat.

If you build the pepperbox front end, it'll go screw -> spring -> smallrainbowrevolvercylinderbase -> smallrainbowrevolverfront. You'll want craft foam to seal between the cylinder and the front.