I wanted the gun to look bigger and a bit more bulky but retain the original design. The original screw can be used for this barrel. Maybe you have to enlarge the 3mm hole a bit depending on your print quality.
I printed it ~5 hours with 0,15 layer high at 50mm/s with supports touching buildplate on my Ender 3.
Sizzling_Jofo.stl | 296.5KB |