ATF Will Let a Factory Rebuild Your Can — If the Serial Tube Survives

ATF dated an open letter to all FFLs August 28, 2026, and posted it September 8. A complete suppressor already registered in the National Firearms Registration and Transfer Record may be repaired or have its caliber changed without a new NFA making, marking, or registration process — so long as the work does not destroy the serialized frame or receiver, alter required markings, or otherwise create a new firearm.

That reverses the 2008 posture that treated drilling baffles or end caps for a larger caliber as making new silencer parts, each a separate firearm. The new letter’s example: enlarging openings in a registered .22 suppressor so it can pass a 9mm projectile. ATF now says those modified components remain part of the registered complete suppressor and the caliber change will not result in “making new parts.”

Qualified manufacturers may obtain unregistered, unmarked suppressor components from other qualified manufacturers and install them as replacements. Once installed, the part becomes part of the marked, registered device and may go back to the registered owner. Rethreading may cause a “minimal” reduction in outer-tube length. ATF does not define “minimal.”

The serialized housing is still the wall. Destroy it, grind the markings, or swap in a new tube with the old number, and ATF says you may have made a new NFA firearm. Loose baffles, spare end caps, and home installs are still inside the silencer definition. This letter applies to complete suppressors already in the NFRTR. It does not expand the Silencer Shop injunction or cover Form 4473 cans that never entered the registry. ATF recommends notifying the Bureau so the NFRTR can reflect a caliber change. That is a recommendation, not a new Form 4.

Guidance is not a statute. A future administration can rewrite the letter. Until then, send the can to a manufacturer who is allowed to touch it.