Why 6
When the current AG in MN was asked how to stop these mass killings, he said limit magazine capacity as well, he mentioned that when he goes turkey hunting he only needs two shots. When I go deer or wolf hunting I only need two shots. But the thing is turkeys, deer, and wolves don’t shoot back, bad guys do.
First of all, who is going to volunteer to go collect all the magazines there are currently out there, likely in the tens of millions. And who is going to collect them from the bad dudes?
Second, the Supreme Court has already ruled a couple decades ago that a jurisdiction cannot legislate magazine size below what the feds say, it is after all, a federal constitution. That the SC is even more conservative today makes it unlikely they will reverse this.
So in short, your suggestion to lower magazine size ain’t gonna fly.