Journalists often mistake the “AR-15” semi-automatic rifle, sometimes referred to as an assault weapon, for an automatic weapon. It is a much smaller caliber version of the military and fully-auto M-16. The AR-15 is also highly accurate at a long distance.
Same caliber bullet, same cartridge. The only difference is the AR-15 is not capable of fully automatic or burst fire. There’s a difference in the receiver and the internal bits to make this so. The accuracy of an AR-15 is the same as the M16 when it’s set to semi-auto.
Gun opponents have lobbied for decades to make “high capacity” magazines illegal. Generally, they are talking about magazines that load more than 8 rounds. An experienced shooter can easily reload with a fresh magazine in a few seconds.
Generally they are talking about magazines that load more than 10 rounds, because I suppose they feel like that is a nice, round number.
But I’ll give the author credit for mostly getting it right. Years ago this stuff was often wildly off the mark.