Magazines are classified as part of the armament, they fall under the 2nd amendment. I know this because Security Forces submitted a 'Process Improvement' idea to the MXG to switch over to 'drum magazines'. First expert from DoD to respond to our inquiries explained all parts/pieces are intentionally specific to the armament so as to ensure nobody attempts to change it & it maintains it's protection under the 2nd amendment. You can restrict scopes because they have alternate uses but the magazine has a set number of rounds based of the cyclical rate of the weapon as designed per the manufacturer.
The more you know…