Did you read the rest of the bill?
It's another deterrent for concealed carriers. If you commit a misdemeanor then it automatically gets bumped up to a felony regardless if the gun was even operable.
So don't fill out a form properly, drive too fast, or ask a public official too many questions and you're looking at a two spot 
Excessive speeding is a petty misdemeanor. IDK if that and "misdemeanor" are the same. But you're onto something here. This is why HI pushed the "duty to inform" law/ordinance. They want to catch you armed and add more charges.
I googled "misdemeanor examples" and this is what came up.
"Minor drug offenses, such as possession.
Drunk driving.
Petty theft, including shoplifting.
Minor or simple assault or battery.
Trespassing.
Vandalism.
Minor sex crimes, including solicitation, prostitution and indecent exposure.
Resisting arrest."
If the SB3196 passes, then having a rifle mag is a misdemeanor. But this bill would increase it to a felony if you're shooting with said mag as you're in possession of a firearm at the range. In HI, a firearm misdemeanor means you lose your 2A right for 20 years. But not true in other states. But now this is a felony, you lose your 2a right nationwide.