Streamlined Knockout Short Dart Mod * Silly Thread O-Ring Collet * 16mm Barrel * Nerf Rival

Streamlined Knockout Short Dart Mod

airtight O-ring seal with Silly thread collet for 16mm (aluminium) barrels.

I wanted to give my Knockout some SciFi vibes, so I tinkered around with BanBot's mod. 
I've once again modified, combined and mixed files from various designers.
This is the result^^

Changes made to BanBot's cool and well designed Extended Knockout Short Dart Barrel Mod:

• reduced the length of the barrel
• opened the inner diametet to 16,2mm (suitable for aluminium barrels)
• integrated the thread of the Silly SCAR in the barrel
• added a screw hole for a M3-20mm screw to secure the aluminium barrel
• added a futuristic and streamlined front sight, adjustet to my slide-on rear sight
• added a small chamfer to the upper edge of the guiding-rail so that no supports are needed
• reduced the height by 0,2mm so the barrel can slide out easier and is forgiving a bit more printing tolerance
• added a DL44 Style flash hider muzzle (for even more SciFi vibes^^) and a Silly SCAR in silencer style.

I have installed a 200mm aluminium barrel atm (but shorter and a little longer also works well). 
I've also included files for printed barrels in case you don't have a suitable aluminum barrel available.


The assembly is simple and should be clear from the photos.

BanBot has also created a good and detailed assembly guide, which you can find here. 

You need one or two o-rings (similiar to the Silly SCAR) for seal between the Silly threads and alu barrel and possibly one M3-20mm Screw to additionally secure the barrel (if necessary).
 

• UPDATE 25.9.2025:
  I added a Foam Cutter to make an additional gasket out of 2mm crafting foam. 
  If your  air seal in the section between plunger tube and barrel is not quite optimal only with the stock o-ring you can glue this foam gasket around the dart gate using E6000 or similar (see photo).
  
  (With this additional foam gasket I managed to create such a good seal that you can stop the plunger by holding the barrel closed with a finger)
  
  The foam cutter works best if you press it onto the craft foam and then move it back and forth in circular movements on a scratch-resistant surface while applying pressure. It is sometimes also helpful to turn the foam sheet over and use the foam cutter on the other side as well, in the pre-cut shape. Simply slide it back and forth until you have completely cut out the foam. Do not try to rip the foam out when it is not all the way through, otherwise the seal might tear. You can then use a piece of filament to push the foam gasket out of the foam cutter through the small opening at the side. 

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The files are already pre-oriented.

My print settings for PLA:

0,2mm layer height
4-5 walls
15-20% gyroid infill
7 top and bottom shell layers
no supports needed
(print with outer brim if you have poor bed adhesion)

Thanks to BanBot, Sillybutts, ehdrien and dysclarity for the files I could use for this remix.

• reduced the length of the barrel
• opened the inner diametet to 16,2mm (suitable for aluminium barrels)
• integrated the thread of the Silly SCAR in the barrel
• added a screw hole for a M3-20mm screw to secure the aluminium barrel
• Added a front sight, adjustet to my slide-on rear sight
• Added a small chamfer to the upper edge of the guiding-rail so that no supports are needed
• reduced the height by 0,2mm so the barrel should slide out a bit easier and is forgiving slightly more printing tolerances
• added a DL44 Style flash hider muzzle