[Spats McGee]

It's not that the AG's office doesn't know what it's doing. When interpreting a term used in a statute, the courts look first to see if the legislature has defined a term. If not, they go with the 'plain and ordinary meaning,' however that may be phrased in your particular state's case law.

As for the SBR, it may well be a "firearm" for purposes of State law, but it is also an SBR, for purposes of federal law. The two are not really mutually exclusive. IOW, you're wise not to ignore Federal law on those.

ETA: I've had to cite Webster's New Collegiate Dictionary as a source before.