A replica of M4 muzzle brake (M4QD-type), designated for use with KAC QD suppressor replicas, but can also be used alone.

The muzzle brake should be screwed onto the replica (CCW thread) so the windows are facing upwards. Use the enclosed "M4 Flash Hider Timing Washers.3mf" to print a set of washers of thicknesses between 0.2mm and 0.9mm (in steps of 0.1mm) to adjust the timing.

You can optionally use a headless M3 headless Allen screw to fix the flash hider in place. Do not overtighten!

Fitting Issues Troubleshooting

On a perfectly tuned printer with a quality 1.75mm filament it should nicely snugly fit the threads on the barrel. In case you find it too difficult to screw on, try to decrease filament flow rate by a few percent.

KAC QD Suppressor Replica

I have also designed a full replica of the KAC QD suppressor that can be found here.

Updates

2024-04-23

• Improved toughness
  • Diameter of the two neck grooves increased from 17.5mm to 18.0mm (anything larger could affect locking mechanism on some QD suppressors)
  • Added chamfering to the lower groove, the same way it was on the upper one
  • Unnecessarily long thread decreased from 20mm to 15mm 
• Updated MK4 printer profiles → upgraded PrusaSlicer to 2.7.4 and MK4 firmware to 6.0.0
  • Support for MK4 Stealth Mode

See Also

My other suppressor models are available here:

• KAC QD Suppressor Replica
• Surefire SOCOM 556 RC2 and RC Suppressor Replicas
• Surefire SOCOM 556 RC3 Suppressor Replica
• Surefire SOCOM 762 RC2 and RC Suppressor Replicas