AR-15s are hunting weapons for many people. So it would impact those. It's not a preferable deer hunting rifle, but I've known people who use them for coyote hunting and varmint hunting.
There are already minimums on barrel length of a rifle.
I think overall minimum length, semi-automatic, detachable magazine would be a place to start as far as regulating current AR-15 and similar weapons, but then a day later there is a model that meets the min length, has a large internal magazine, and wouldn't you know it the gun industry has designed a weapon that doesn't classify as semi-automatic yet can be fired almost as fast.
Look to the last AWB and the way the industry and customers found ways around the regulations.
Let's keep in mind these are semi-automatic rifles with detachable magazines that are relatively short.
The one on the bottom shoots .22 cal rounds that are on the very low end as far as "power" is concerned, even compared to moat handguns. There is almost no way you could ban AR-15s and not ban that Ruger 10/22.