From Guns.com:

First, it would institute a program to require ammo dealers to obtain a license to sell their products to consumers. Current federal law only requires a license for those engaged in importing or manufacturing ammunition, not to sell, purchase, or possess. This would inevitably have the effect of trimming the number of legal vendors to the marketplace. 

Next, Coleman’s bill would require face-to-face transfers of ammunition from licensed dealers to consumers, which is a departure from the common practice today of gun owners searching for deals through online sites such as Guns.com to fill their ammo needs. This would be further enhanced by a ban on shipping ammo to anyone without a license.