ATF Watches Ghost Guns, Glock Switches

ATF's Middle Tennessee field office says ghost guns are fading, but Glock switches are filling the gap.

Driving the news: ATF shared new data on firearm trends in the Nashville area, flagging a shift from untraceable ghost guns toward auto-conversion devices that can be printed for next to nothing.

Catch up quick:

• Ghost guns are home-built firearms, often 3D printed, with no serial numbers
• Glock switches are small add-on devices that convert semi-auto handguns to fully automatic fire—legally classified as machine guns
• Both can be manufactured with a consumer-grade 3D printer

The tool ATF is leaning on is a system called NIBIN—a national database that matches shell casing markings found at crime scenes. Even without a serial number, a recovered casing carries unique toolmark signatures from the firearm that fired it. Agents photograph casings and run comparisons across the database, sometimes linking a single gun to a half-dozen shootings.

"We can show this particular firearm that was recovered was linked to 4, 5, 6 other shootings—that suspect is a priority target for us." — ATF Special Agent in Charge Jamey VanVliet

By the numbers:

• 10 ghost gun casings entered into NIBIN in Middle Tennessee in 2024
• Over 1,000 total casings in the regional database over recent years
• Ghost gun kits have been under increased federal enforcement pressure since 2022

Reality check: Ghost guns were never the dominant threat the headlines made them out to be—at least not in this region. Ten casings in a full calendar year is a rounding error in a metro Nashville crime context. The crackdown on unfinished-frame kits appears to have worked, at least for now.

The sharper concern is the switch. Glock switches—and their functional equivalents for other pistol platforms—convert a standard handgun to fire continuously with a single trigger pull. That makes them machine guns under federal law, carrying up to 10 years per count. But the deterrent only works if you catch the guy first, and a switch printed at home in under a minute leaves no purchase record to follow.

What to watch: VanVliet described switches as a top enforcement priority. Expect ATF to push for NIBIN entries on auto-fire casing patterns—the cyclic rate of a switched gun produces a distinctive casing ejection signature that may be identifiable in the database even without the device in hand.