The AR-15 was NEVER fully automatic and are NOT banned. Clinton banned them after Columbine but that ban was temporary and Bush never renewed the ban. Fully automatic rifles are NOT banned. It is just very very very hard to get a license for one and it is very costly to buy and get licensed for a fully automatic.
As far as function, speed and accuracy there is no difference between an AR-15 semi-automatic rifle and something like a Ruger Mini-14 Ranch Rifle. Both fire the the .223 round and bother are semi-automatic rifles. An AR-15 makes leftists wet their diapers in fear while the Ruger Mini-14 has a wood grain stock that only the most haplophobic leftists will need their diaper changed.
BTW the Ruger and other hunting rifles, semi-automatic or bolt action, are for small game because the .223 and the NATO 5.56 (which is the same size as the Remington 223) are not killing rounds. You can kill someone with that round but it isn't as easy as a larger diameter bullet. NATO recommended going to this size so fewer soldiers come home in body bags.