This is actually false.
There are not mass shootings with ARs every week.

Look at a website like mass shooting tracker, and actually READ some of the incidents. Most are like 'victim1 and victim2 were leaving a house party on Crescent St. when suspect1 and suspect2 opened fire from a moving vehicle. Victim1 and victim2 returned fire and all four young men were wounded, along with bystander1 and bystander2.' This will qualify as a mass shooting because four or more people are wounded, so it shows up on that stupid tracker. But there is no AR anywhere, just pistols. Read between the lines and you realize this is a gangland shooting. And in all likelihood all four firearms are illegally owned.

Reality is more people are punched and kicked to death every year than are killed by all rifles including ARs.

Furthermore, there are several million ARs in circulation, and only a couple hundred rifle deaths every year. From a pure statistic point of view, that makes it actually a pretty safe product.