Piltover Enforcer's Rifle from Arcane

This is a prop rifle based on the one used by Piltover Enforcers in Arcane. It is also prominently used by Caitlyn during the first episode of season 2.

The prop features a spring trigger (you can pull/release it, but it doesn't actually do anything) and a reload lever that opens the hatch on the side of the chamber (which would eject the spent casing and chamber a new bullet, had the rifle been real).

The CAD file is available online in onshape. This can be used if you want to tweak anything, or just as a reference when assembling.

I had to do some adjustments on the fly while printing mine, so while I haven't printed this exact version myself, all the tolerances should be right ones.

Required Components

• 1 small compression spring 
  • 5mm diameter and 10mm long (approx, inner diam is 3.2mm)
• 1 hair band or rubber band
  • 2mm string diameter, 14cm circumference. These are just the standard thin hair bands I can buy in a clothes store.
  • When assembled, the hair band is folded double to get the correct tension.
• 2 round wooden rods
  • One 12mm diameter, 26cm long (make it just a couple mm shorter)
  • One 12mm diameter, 55-60cm long
• Some glue (I used super glue for plastic-plastic and hobby glue for wood-plastic)

Assembly

These are some fairly detailed instructions, but I'm sure you can figure most of this out yourself too! Especially if you have a look at the CAD file in onshape (link above).

1. Hook the hair band onto the hook inside the housing, fold it on itself and hook it onto the same hook again. You want the hairband to be a double loop. 
2. Hold onto the double loop and pull it outwards so that you can mount the hatch into the housing and secure it with the hatch hinge.
   • Tip: instead of holding onto the double loop with your fingers, insert a pen through the loop while you mount the hatch.
3. Mount the housing to the chamber, but do not secure it with the bolt yet.
4. Insert the lever into the chamber and secure it with the lever bolt.
   • I also put some 1-2mm thick double-sided tape (but without removing the protective film from the outer side, so that it's not sticky) on the top of the lever to make the surface where it interfaces with the hatch softer and always be under slight tension. This prevents any rattling sounds from the lever.
5. Put the spring around the little cylinder inside the handle. You probably want to use some pliers.
6. Mount the trigger to the handle by inserting it through the trigger hole, then pressing it down on the spring while you insert the trigger bolt.
7. Glue half of "plug barrel 1" into barrel 1.
8. Glue half of "plug barrel 2" into the thick end of barrel 2.
9. Glue half of “plug chamber” into barrel 3. 
   • Make sure you glue the side that doesn't have a hole.
   • Check the orientation. After gluing, the hole should be visible and be closer to the rifle barrel.
10. Glue the 55cm round rod one section at a time, and insert it into barrel 1, 2 and 3. There should be about 5 cm of room between the muzzle and the rod, and on the other side, the rod should poke out 5-8cm past the end of barrel 3.
    • While gluing, you may also glue the other halves of plug barrel 1 and plug barrel 2.
11. Insert the rod into the chamber.
12. Secure the barrel to the chamber using "plug chamber bolt".
13. Glue the 26 cm rod and “plug stock” into the stock.
14. Glue the stock to the handle.
15. Attach the handle to the chamber and secure both plus the housing using the hatch bolt.
    • (Optional) Put some double-sided tape with just a little bit of thickness to it (I used carpet tape) between the flat parts of the chamber and handle before pushing them together. You may also glue this surface instead, but tape makes disassembly of the handle easier should it be needed, while still providing some extra stability.
16. Insert the barrel cap into the muzzle in case you plan to bring it to a public space. The cap should be printed or painted orange.