[steve-b]

Who should the lower court have asked to testify on the suitability of the weapon for a state militia?

The same people they ask about any other questions of fact that affect a case before them -- the expert witnesses supplied by the parties to the case. Presumably, the expert witnesses will have different takes on various points, in which case it falls to the court to decide who is more credible.

[robertpaulsen]

Ah. So the states have no say in the matter. They are not allowed to testify in court as to what weapons THEY consider useful to their own state militia. Some "expert" will do that for them. He'll tell all the states what they can or cannot use to defend their state and our country.

That makes sense.