Why doesn't the OP show off his brilliance and skills by posting a draft here of the statutory language he feels would be adequate?
Confucious say: It is easy for small minds to criticize rather than actually do something.
The OP may well believe that belt fed firearms have legit sporting purposes for all we know at this point.
All of this stuff about magazine size and assault weapons is designed to avoid discussion about the weapons used in the vast majority of gun violence and gun accidents in this country- handguns. Nobody wants to talk about that, at all, so it just doesn't happen.
I'm sure that there are warehouses full of high capacity magazines in this country, making the idea of limiting magazine size in new firearms foolish and distractional, along with much of the rest of it. Maybe if the whack-o-matics of this country decide to implement a "second amendment solution" to the perceived abuses of govt will we be willing to see things differently, but not until.