Video Instructions
Text Instructions
Loosen castle nut with armorer’s wrench. Unscrew castle nut all the way back and slide buffer tube plate back. Don’t lose selector spring and detent if not retained in lower. Unscrew buffer tube.
Install FRAC orientation ring against castle nut.
Install FRAC body with button on the left side of the gun. (Shown upside down. Don’t push the button on the FRAC!)
Thread buffer tube into lower. Align buffer tube to gun and push FRAC up to the back of the lower. Snug down castle nut by hand. Do not thread buffer tube in past the front edge of the buffer tube extension or upper will not install.
Tighten Castle nut with armorer’s wrench.
Remove air line with ¼” wrench.
Install FRAC air line with ¼” wrench.
M4/MTW-9: Use 3.5″ airline.
MTW-308/Shotgun: use 4.5″ airline.
Install engine.
M4/MTW-9: Upside down (airline on top of engine).
MTW-308: Install regularly.
Feed airline through FRAC while holding button, then secure body pins.
Uninstallation
Got a FRAC but want to switch back to a traditional grip line? It’s easy to uninstall. But first you’ll need a standard gripline and your choice of sling plate.
Loosen the castle nut with an armorer’s wrench, and then unscrew the buffer tube from the MTW to remove it. If your FRAC was preinstalled on your MTW when you purchased it, your buffer tube may had a small amount of blue Loctite applied to the threads, requiring a little additional force to remove.
Remove the FRAC and FRAC orientation ring and replaced with your sling plate. Reinstall your buffer tube. Do not thread buffer tube in past the front edge of the buffer tube extension or upper will not install. Tighten the barrel nut.
Remove the engine from your MTW and remove the FRAC air line with ¼” wrench. Replace it with your standard grip line and reinstall your engine.
