Adam Kraut gives a good thumbnail overview of how to respond to the BATFE proposed rulemaking in the video below. He suggests taking a shotgun approach as the more objections you can raise, the more the BATFE has to work to respond to them. Moreover, if it isn’t brought up now, it can’t be brought up in court later.
Here is the document released by the lawyers of the Department of Justice with their legal rationale (or bullshit, to be more honest about it) saying why they can now define bump fire stocks as machine guns. It is important to note that if this rule is enacted then all existing bump fire stocks become contraband unregistered machine guns and must be destroyed or turned into BATFE. Why? That little amendment to FOPA 1986 called the Hughes Amendment comes into play as bump fire stocks were developed, manufactured, and sold after 1986.
Here is the correct link to the comments page.
I say correct link because www.regulations.gov has two links to the proposed regulations. One is the correct link and the other says comments are closed. Remember, never attribute to malice that which can be explained by incompetence or stupidity.
So scan through the DOJ document to find areas on which to make comments. There is nothing to say you can’t make multiple comments on different things. The comment period closes on June 27, 2018 at 11:59pm. So do it now while it is still fresh in your mind.