the problem that they are going to have is enforcement. since there is no longer any chance of a federal ban happening any time soon, no manufacturer is going to stop making the high capacity magazines and none will start giving date stamps or marking M&P use only for their high cap mags.
as colorado can not confiscate existing magazines or penalize anyone for owning magazines manufactured prior to the ban it is therefore legal to possess any non date stamped magazine(which is almost all of them) or magazine stamped prior to the law.
so it would be just as simple to take a drive up to wyoming(or other bordering state) and buy high capacity magazines with cash and state officials would never be able to prove that you are illegally possessing a high capacity magazine.
all guns lost in a tragic smelting accident.
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