Another point is that the interpretation of the ATF's own rules can differ from one agent to the next. I was able to attend a seminar recently where various agents of the State Police, Sheriff's Office, ATF, and local and state officials gave comments on various topics such as home defense, concealed carry, NYS pistol regulations, etc. The ATF agent was particularly illuminating, and his advice on whether a firearm was in compliance or not was to call him and ask.
FWIW, he seemed like a nice guy.
