Dave Markowitz pointed out this section of the United States Code I had never seen before. It deals with federal regulations concerning toy, look alike, or imitation firearms, and requires the orange barrel that anyone who has ever bought an Airsoft gun in this country is familiar with. But it contains this provision at the very end:
(g) The provisions of this section shall supersede any provision of State or local laws or ordinances which provide for markings or identification inconsistent with provisions of this section provided that no State shall—
(i) prohibit the sale or manufacture of any look-alike, nonfiring, collector replica of an antique firearm developed prior to 1898, or
(ii) prohibit the sale (other than prohibiting the sale to minors) of traditional B–B, paint ball, or pellet-firing air guns that expel a projectile through the force of air pressure.
This is worded in a confusing manner, but my read of it is that the preemption is limited to marking requirements, meaning if New York City were to require that all imitation guns be painted bright pink, federal law would preempt that, provided that New York State does not outright prohibit the sale of look-alike arms. By the same token, Philadelphia would be unable to stipulate markings for an imitation firearm because Pennsylvania does not fall under the exception.
I could be reading this wrong though. Because the way it’s worded, it seems to be that you could read it that if any state passes a law along the lines of (i) or (ii) the entire preemption would be nullified.