Here is a link to the new ATF handbook. This may be the one that NFTCA has been helping out with????? https://www.atf.gov/firearms/national-firearms-act-handbook
Thanks, a lot to learn; my only question is: "But if the dealers receipt and disposition of these devices become repetitive, ATF may infer that the dealer is engaged in the business of dealing in the devices and require him/her to be licensed as a dealer in such devices. There is no precise number of transactions that would trigger the license requirement." interesting.....................
An updated NFA Handbook was posted on the ATF website today (22 April, 2009). http://www.atf.gov/press/2009press/042209nfa_handbook-updated.htm
Just as there is no set number of firearms a person can sell without a license. Defined as "intent" to make a profit as a regular course of business. The law has been left very "gray", that's the way lawyers do things.
https://www.atf.gov/firearms/national-firearms-act-handbook I think all of the links above were dead but this one is current.