Ive said that will be the next form of gun control for about 8 years now. How to control guns is to control the ammo, constitution doesnt give you the right to buy cheap ammo.
Ban ammo importation for "safety" and then tax the ever living daylights out of domestic production until pistol/rifle rounds are $5ea and shotshells are $100 a box. Now you have gun control, people aren't going to visit ranges and hunters will give up which will please the animal rights people. Demand plummets so used guns have no real value, now people are going to sell their guns in the state buyback programs where they will be destroyed, because they cant afford to shoot them.
They also need to implement those taxes and write in that anyone manufacturing their own ammo has to pay the tax quarterly. Now you can arrest reloaders for tax evasion when they do not pay and stop that side too.
Once the supreme court stops all these "common sense gun control laws", theyll go after the ammo.