They could but why bother doing so? A ban is a waste of law enforcement resources. Oh, I know, Nafod - you're a soldier and thus are an expert.
Let's see what other experts think....
In 2016 the FBI reported that 374 people were killed with rifles out of 15,070 murders. Knives were used 1,603 times, firsts were used 656 times (see https://ucr.fbi.gov/crime-in-the-u.s/20 ... able-4.xls ). So we're talking 2.5 percent of murders from using rifles.
The FBI does not have a category "Assault weapon". Just rifles..... fair enough to say that "rifle" covers it?
Leading causes of death for US persons.
Heart disease: 633,842
Chronic lower respiratory diseases: 155,041
Accidents (unintentional injuries): 146,571
Stroke (cerebrovascular diseases): 140,323
Alzheimer’s disease: 110,561
Influenza and Pneumonia: 57,062
Nephritis, nephrotic syndrome and nephrosis: 49,959
Intentional self-harm (suicide): 44,193
So a person in the US is
1695 times more likely to die of heart disease than be killed with a rifle
1497 times more likely to die of cancer than to be killed with a rifle.
415 times more likely to die of chronic lower respiratory diseases than to be killed with a rifle
and so on....
The sum total of the top ten causes of death is 2,013,017 people. Those 374 unfortunates are very unlucky, as they're 5,382 times more likely to have died of the top ten causes combined.
If it weren't for Oligarchs and their hired henchmen we probably wouldn't be having this discussion at all. Mike Bloomberg and a few other super rich Progressives are bankrolling a lot of the 'gun control' in the US.
Focusing us on the 'problem'.... which is not much of a problem... unless it's in your face day after day thanks to the Corporate owned Media.