[duchenne]

If they are worried about firearms, why don't they target CNC mills rather than 3d printer? Can you even make a firearm in plastic?

Some US company specialize in selling CNC mills specifically for firearms.

Ex: https://realghostguns.com/product/gg3-s-cnc-deposit/

    It is sold with the cut codes for the AR-15, AR-.308, 1911, Polymer80 and AK-47 receivers and frames.

[ale42]

Article says:

  New York’s budget bill S.9005 buries similar requirements in Part C, sweeping   
  in CNC mills and anything capable of “subtractive manufacturing.”

So CNCs might be part of it. But I didn't check the actual bill text.

[burnt_toast]

> Can you even make a firearm in plastic?

Yes but most designs still require metal bits. Typically the frame will be 3d printed and then you rely on machined components for things like slides and rails.

[preisschild]

Theres also electrochemical machining which is rather easy to do at home