Variation of the zip-gun and why our ruling establishment wants to stomp out any ability/desire of the citizenry to assemble arms. Sucks to be Abe, but he's martyr now. We'll see how that one pans out.
Look no farther than some of the home made guns made inside our prisons! When I worked at a FL State Prison many years ago we confiscated a gun that was fabricated out of a metal chair leg loaded with a 3" .410 shotgun shell. That incident was the primary reason the DOC switched to the plastic type patio chairs for the visiting areas.
So what will Dems do about 3D printers? I haven't really kept up with the guy who pioneered printing AR lowers. Initial challenge (years ago) was durability of available "ink". I think he'd gotten up to around 1,000 rounds until failure of lower the last I looked--still pretty respectable. So, a PDF file of layout and a 3D printer allows hi cap mags and lowers to be printed. I'm sure durability is better now and likely only will improve.
Who knew computers might actually "set us free". Modern day equivalent of a home foundry. Will Dems ban the personal computer and 3D printer next?
I'd imagine this risk was a motivator of the chatter about serializing every major part of an AR. That way you can control the much more difficult to "make at home" parts.
Democrats will try to prevent you having anything to protect your life and property with ,they prefer defenseless victims. It seems they have a lot in common with there brothers in the b.l.m. mob .