Not sure if this is the right location for this thread but mildly interesting news from ATF
https://content.govdelivery.com/accounts/USATF/bulletins/22189c1
Effective immediately, any requests for a determination on how an accessory affects the classification of a firearm under the GCA or NFA must include a firearm with the accessory already installed. Except in cases of conditional import determinations, FTISB will not issue a determination on an accessory unless it is attached to the submitted firearm.
If you have previously submitted a sample accessory for classification, FTISB will be returning your sample without classification. FTISB will contact you in the near future with further instructions to facilitate the return of your sample.
https://content.govdelivery.com/accounts/USATF/bulletins/22189c1
Effective immediately, any requests for a determination on how an accessory affects the classification of a firearm under the GCA or NFA must include a firearm with the accessory already installed. Except in cases of conditional import determinations, FTISB will not issue a determination on an accessory unless it is attached to the submitted firearm.
If you have previously submitted a sample accessory for classification, FTISB will be returning your sample without classification. FTISB will contact you in the near future with further instructions to facilitate the return of your sample.