Kickback Masterkey: A Nerf Mega XL Blaster Attachment

A Nerf blaster attachment that shoots MXL, using the plunger tube of an XShot Kickback blaster. Need to shoot special zombies or bust shields, but don't have the hobby hardware for a plunger system? Look no further!

There are two filesets currently: one that attaches to a Nerf rail (and Rival rails), and one that attaches to Picatinny. They use the same hardware. You can also mirror the entire thing to have the triggers be on the right side instead of the left.

Hardware Required:

• XShot Kickback Blaster (Shell Screws x9, Plunger Tube, and Spring)
• 11/16" ID, 1/16" Thickness O-Ring (Air seal to MXL spigot)
• 5in of 6-32 Threaded Rod (x3) (Rods)
• 6-32 Nuts (x8) (Rod and Rail Securing Nuts)
• 6-32 x 1.5 (x2) (Rail Securing Bolts)
• 6-32 x 0.5 (x1) (Sear Pin Screw)
  • May also be replaced by an M3x12 screw, using appropriate Searblock file
• 1/8" Shock Cord (approx. 6in) (Sear Elastic)

Shoots MXL at around 30 FPS, which is enough to shoot about 5 yards (enough to shoot a zombie ;D). Can additionally shoot standard darts with the inside of the spigot. And yes, you can stack them.

Rough assembly guide:

1. Extract the plunger tube from the XShot Kickback and unscrew the plunger head from the plunger stem.
2. Put the plunger stem through Searblock and Back Cap such that the catch cutout is on the same side as the slot where the sear goes. Put the spring around the stem and reattach the plunger head.
3. Remove the orange barrel from the plunger tube and place the O-Ring around the thin, raised lip on the plunger tube. Insert the tube into the Plunger Shell.
4. Place the Spigot and then the Front Cap on the front, such that the Front Cap presses the Spigot against the O-Ring. Insert the bottom two threaded rods into the bottom two holes and tighten nuts onto each end such that the nuts are horizontal. You can tighten as much as you want. 
5. Place the Picatinny Rail on top of the assembly, and insert the threaded rod into the top hole. Tighten nuts onto each end, but do not tighten past finger tight.
6. Insert the sear into the searblock and pin it using either the 6-32x0.5 or M3x12, depending on the Searblock you printed. Thread the shock cord through the bottom hole and tie it around the entire attachment as tight as possible.
7. Attach Front Cover and Back Cover to the front and back using the shell screws from the Kickback. You may need to prime the attachment to attach the Back Cover.
8. Use the Rail Securing Bolts to attach it to whatever you would like. Enjoy!

Metric version coming soon.