A letter to the CFC is REQUIRED to deregister a dewatted firearm and must be submitted by a verifier. I also include a detailed list of what has been done to deactivate the firearm, it is not necessary, but makes the paperwork sail through no problem. The key to dewatts is that the gun must be not be able to be "reactivated" without the use of machine shop equipment. Pouring #### in the barrel will not do it. In the MGs I have done, I drill a 3/8 hole through the barrel from the bottom, drive a drill bit in from the chamber and weld it in place, Mill off the front of the bolt, remove the firing pin. Then reassemble the firearm and tack weld all the pins and hinges or takedown parts that hold the gun together. I also for good measure weld the muzzle closed, more so that it is plainly visible that the bore is plugged. If you are doing it yourself I would recommend taking photos of the operation in case someone at the CFC wants to see what you performed.
My welds are under 1/8th " across and so far none have been challenged, with some finesse you can get an arc established inside the bore back of the muzzle and at 10 feet it will not be noticed. :mrgreen:
