The only reason.....
the "gun trust" was invented was because CLEO's {Chief Law Enforcement Officer's} were arbitrarily not signing off on ATF Form 4's. If you can pass a NICS check, you can purchase NFA firearms. The Form 4 requires the CLEO to sign stating that he/she knows you, & knows of no reason why you shouldn't have the NFA item. If they don't sign, they aren't required to say why. It could be because he could never catch you speedin' thru town as a teen in high school. It could be because you punched his grandson in the nose when the two of you were in grade school. It could be because you're a rival political opponent. The trust get's past the arbitrary stuff.
There are other ways as well. If the local PD chief won't sign, go to the sheriff. If he won't sign, go to the local state police post commander, or the head of the state police, the local DA, & the state attorney general, also have been used.
The 1934 Group took the CLEO sign off all the way to the SCOTUS, arguing the CLEO signoff & NFA of 1934 were in violation of The Second Ammendment, & they refused to hear the case.
I've been involved in NFA firearms for over 30 years, & the only case involving a LEGALLY REGISTERED NFA MACHINEGUN happened in Dayton, some time ago, when a narcotics officer got tired of a multiple convicted dope dealer, getting off time & again on technicalities. The last time, he waited for the dope dealer to come back home, & hosed him with his LEGALLY OWNED Mac 10.
All these other cases, involved ILLEGALLY CONVERTED machine guns, or guns that weren't machineguns at all, just semi "assault" weapons & they are few, by the FBI's own statistics.
If you wanna learn more about NFA '34 & NFA Firearms & regulations, go to
Subguns.com. This is an excellent resource, with links to others as well.
This thread needed some pic's too.
Ned