As far as I knew, they already had. It's been a long time since I was in school, and I was never offered archery as an option. This would make it official across the whole state, I suppose. Perhaps some rural districts offered it and they are determined to shut it down?
They explicitly say they are wanting to shut it down because it promotes "gun culture", which aside from being literally nonsense, may open them to First Amendment challenges.
Confiscation of semiautomatic rifles in Chicago area town
So, once they figure out you own an assault weapon in this town, they want you to give it up to their police force. Not remove it from their jurisdiction, sell it to someone else, or destroy it -- the daily fines continue until they have it in their hands and you do not. That's a definite escalation from other attempts at gun bans that have focused on banning new manufacture or sale while grandfathering existing firearms.
The actual ordinance is more precise. It's a one-feature test. Semiautomatic, capacity to accept a detachable magazine, plus one feature (including a pistol grip, forward grip, thumbhole stock or other scary stock types, shroud, or anything scary on the muzzle).
In practice, that means almost any semiautomatic firearm with the capacity to accept a magazine regardless of size (since you can always find a standard-capacity magazine).
His take is about the same as my take: some guy reloading ammunition as a hobby and occasionally selling the results of his work. Consensus seems to be so far that the armor piercing element of the charge is somewhere between complete bullshit and a technicality, and we're not going to know which without knowing the details of the ammunition that was found. I don't have any idea what the law on manufacturing and selling tracer rounds is.
In a Democrat administration we'd get some BS gun control laws passed over this. I bet the ATF is salivating over the possibility of eliminating or regulating reloading if the House turns over to Democrat hands, figuring they can pick up enough Republican squishes in the Senate and pressure Trump to sign it.
Folks, we're going to have to keep an eye on this. It's not going away.