Reply #22: It's as difficult as making a new machine gun

[Recursion]

To do that you would have to make a new machine gun and put it inside the "automatic-looking" body of the rifle. But if you can make the new machine gun, the unavailability of tactical-looking accessories is not what would keep you from doing that. And it's just as easy to convert a more traditional-looking rifle to fire automatic as it is to convert a military-looking rifle.

(Note: in the 1980's there were a few models that could be converted more easily; these loopholes were addressed and those weapons are now covered by the same laws that govern out-of-the-box automatic weapons.)

Having a grip that protudes vertically from the body of the rifle, or being painted black, does not make a gun operate any differently. It just makes people's perception of the gun very different.