Democrats have been saying that for 30 years. The excuse that you need guns to prevent the government becoming tyrannical was a farce since 1900, there's no way that individuals with AR-15s could overthrow the military unless the military lets them do so at which point you didn't need the AR-15s in the first place.
You can make an argument for home defense or hunting, but a shotgun or bolt action rifle are generally more than enough for that.