Airsoft KWA kz.61 GBB TM-Spec Outer Barrel Assembly (WIP PROTOTYPE)

THIS IS A WIP PROTOTYPE!

Replace your KWA-spec barrel and bucking with a TM-spec barrel and bucking! Unlike most other brands, KWA still uses their own design for barrels and buckings, reducing the availability of performance aftermarket upgrades. To fix this, I designed a 3D printable outer barrel assembly compatible with TM-spec components.
 

Barrel Types

TDC Hopup

The TDC (Top Down Center) hopup adjustment method uses screws or grub screws to adjust the hopup. TDC is the cheapest, simplest, and easiest to implement hopup adjustment method. This method however, requires a hole all the way to the barrel for ease of adjustability.

Screw Adjustable Hopup

This method uses a bracket (ideally a metal one) to transfer force onto the bucking, similar to a Hi-CAPA. A screw is visible to the user from the bottom of the upper receiver when the body pin is removed that is used to adjust the hopup.

Required Hardware

TDC

• 3x M4 grub screws with smooth bottoms
• 1x TM-spec GBB pistol barrel
• 1x TM-spec GBB bucking

Screw Adjustable

• 2x M4 grub screws with smooth bottoms
• 1x M2 countersunk screw
• 1x TM-spec GBB pistol barrel
• 1x TM-spec GBB bucking

Required Modifications

• The KWA-spec bucking has a little flat spot on the bottom where the nozzle interfaces with the bucking. This must be cut into the TM-spec GBB bucking you intend on using.
• Minor sanding and filing may be required due to tolerance of most 3D printers being quite poor.
• The grub screws need to have a smooth bottom for proper barrel gripping and hopup adjustment.
• Anti-reversal ledge on the TM-spec bucking may need to be modified or removed, depending on which barrel you choose.

 Important Info

• Do not over-tighten the grub screws! Most barrels are brass or other soft metals.
• Make sure the grub screws do not protrude past the barrel, otherwise it will scrape against the bolt!
• There is a little bit of room to adjust the seating of the nozzle. If there's no air seal, move the inner barrel closer to the nozzle.
•  It's HIGHLY SUGGEST you don't make any permanent modifications to your kz.61, as this is a prototype and things will likely change.

Print Settings

• ≤0.2mm layer height
• Supports optional (except for the Barrel Spacer)
• Strong material recommended