My life is important, too

Elected officials seem to need to do something, even if it’s wrong, in response to the Sandy Hook massacre. The leading thing now seems to be a limit on capacity (number of rounds held) for rifle and pistol magazines. Both the NY State legislature and our President want such a limitation.
I guess someone thinks that mass murderers need “large-capacity” magazines, while we good, law-abiding citizens don’t. I don’t see the logic; neither do I think that politicians should be deciding what the Second Amendment lets me do. There was a federal restriction on magazine capacity of more than 10 rounds that expired in 2004; our Prez wants is re-instated; the New Yorkers are considering an over-7 round limit.
NY’s Governor Cuomo, who has obviously never needed to defend himself or his family, proclaimed that “Nobody needs 10 bullets to kill a deer.” Well, I don’t hunt deer, so I don’t know, but our 2nd Amendment rights are not only about hunting. The Supreme Court agrees that it’s also about defense against violent individuals, foreign invaders, and, yes, tyrannical government. When the government fears the people—you have liberty; when the people fear the government—you have tyranny.
Indeed, the Court said, our 2nd Amendment guarantees the right to own weapons “in common use for lawful purposes,” which clearly include guns capable of firing more than 10 rounds without reloading. The Glock 17, one of America’s most popular handguns, comes with a 17-round mag. One of the most popular rifles, the AR-15, comes with a 30-rounder. So good citizens who own mags of 10 or more round capacity are not far-out weirdos—neither are they committing crimes using their firearms. There are already lots of those magazines out there now.
Oh, for you politicians who have never changed a magazine, as I did in combat many times, changing mags takes 1-3 seconds, which will rarely make a difference in attacks on unarmed people. The Sandy Hook gunman apparently changed his 30-round mag at least 4 times; he stopped only because police were closing in.
Speaking as a combat infantryman, magazine size is more likely to matter for people defending themselves, which is why it is insane for the government to declare that no one needs to fire more than X number of rounds. There are various scenarios, including riots, home invasions, and gang attacks, in which a large-capacity mag can make a crucial difference, especially when you recognize that people firing under pressure do not always hit their targets (the adrenaline thing) and assailants are not always stopped by a single round. Based on what we see going on in the Mideast, we may see Islamist terror here in the US. The time to prepare is before things like that happen.
If mags holding more than 10 rounds are not useful for self-defense, shouldn’t the same limit be imposed on police officers and bodyguards (including the Secret Service)? And if the additional rounds do provide more protection against armed assailants, why should it be denied to law-abiding citizens?