If you are concerned about gun rights, this is a far more dangerous path to choose. I'm sure a significant number of people here wouldn't qualify in a lot of people's minds because someone with similar "problems" killed someone in the past. It is also going to keep more "nuts" on the street. Would you seek help if it meant the government was going to take away your guns? One in four Americans have some sort of mental disorder. I expect this is much more than have 100 round clips.
Regarding the "right," I'm sorry but just because a weapon (or accessory) is out there doesn't mean you have the right to own it. A line has to be drawn somewhere between nukes and muzzleloaders and limiting the amount of damage that can be done by the inevitable idiot by limiting clips to 10 rounds is reasonable. If you want to go down like Scarface then simply get a bleeping permit for a fully automatic.
rg