I say ruling, even though I haven't seen it in print, even if it EXISTS in print.
Maybe it's a Determination,or a Opinion which is a distinction without a difference as the end result remains the same.
According to these 2 threads here on Arfcom;
the presence of engravings on a lower suggesting a auto sear pin hole makes the lower a Machine Gun.
All by themselves.
The BATF has impounded at least 2 lowers and their Tech Department has determined they are Machine Guns without intent to make a machine gun (due entirely to the "fake sear pin" engravings), and is calling for the owners to voluntarily surrender them for destruction.
Since all your (Troy Defense) replica GAUU-5 and XM177E2's have this feature engraved, do you foresee any problems selling what BATF has determined a Machine Gun?
Even if this is a case of a overeager Agent, without a clear unequivocal ruling what stops BATF from seizing my Troy?