This is fear porn.
According to the article, the ban is for any ammo that can pierce soft body armor and be found in a handgun platform.
Technically, most shotgun slug ammo is armor piercing, but so far there isn’t a shotgun handgun available (only class 3 shorties) or all slug ammo could be banned under this rule.
Most high velocity rifle calibers are armor piercing even without the steel core (green tip). This would include 30.06 and .30-.30 as well as most high velocity .223, .308, .338 lupua, .50 caliber, etc. Only hard plate body armor can stop these type of rounds and the rule is specific to soft body armor.
This is fear porn.
Why should AP ammo be banned?
Key question: is M855 AP or not? what constitutes a “core”? is the steel component a “core”...or a “tip”?
To express an unpopular opinion: there’s an overreaction here. We’ve been expecting this one for a long time. More like people are looking for “the big attack on our rights” and trying to make this one it. Yeah, M855 is popular - but not dominantly so. They’re not after all .223 et al yet (not saying they won’t be). It’s not the end of feeding the AR15, it’s not the end of “can penetrate soft armor”, etc. Another battle over RKBA, yes, but not the war.
What it _does_ do is get the base motivated, and provide another opening to fight back, with a vague misconstrual of a poorly-defined legal term giving a court a chance to apply “strict scrutiny” and close this line of attack.