It was a seemingly illogical Arizona veto reason,
since the Governor the previous month signed the local Firearms act for locally made and distributed guns, similarly contravening federal regulations, and as seen a similarly constructed HB2307 bill text – but no local iron ore mining or processing for the guns.

The US constitutional inter-state commerce clause is otherwise usually interpreted – as in the other state bills – as banning only significant non-generic component imports for local manufacture.

In other words: Tungsten is used in many other applications, so can be imported – like iron of course can for guns, in that case.

The more specifically applied tungsten filaments or special gun parts can not, so might have to be made locally.
But it seems specific non-generic gun parts are imported to Arizona for assembly!

Federal v local gun law issues include US manufacture of assault weapons for civilians (Hughes amendment to 1986 Firarms Act), as well as licensing and taxation, so such Arizona assault weapon manufacture by the federally licensed local makers contravenes federal law — just as much as the local manufacture of regular incandescent light bulb would.

As always, it’s about local political support:
The gun culture and the extensive manufacturing in Arizona, versus no current light bulb manufacturing, and perhaps lukewarm public support (at least until people realize the bulbs are disappearing, when it’s too late)

So, whatever way one looks at this,
a legally illogical passing of one bill, and not the other.

Federally,
a main issue to stop local production has been discerning locally made produce – as in indian reservations, or in post war wheat production in some states, or california marijuana production more recently.
However, both guns and bulbs can obviously be stamped and discerned in that regard