Some states, like California, and New York (which recently passed the first 3d printer ban), have restrictive gun control. These laws are in conflict with Supreme Court rulings supporting the 2nd Amendment, but the litigation and appeal process is very slow. It is 9 years into the Duncan case in California challenging magazine capacity limits, 7 years into the Miller case challenging California's Assault rifle ban.
Unlike the downvoters, I'm genuinely curious: do you believe a narrative that the US has no gun control laws? Sometimes I wonder if that is what people outside the US think.