In my mind, the entire point of the second amendment (as MARIS61 has stated) is to ensure that the populace is sufficiently armed to protect itself against the threat of tyrannical government. If the populace is relegated to pea shooters and air rifles, it seems that it would defeat that primary purpose.
On the other hand, I might suggest that the "government"--and the country itself--are too sprawling and fractious to facilitate a legitimate tyranny, so perhaps it's possible that the 2nd has outlived it's usefulness.
I would submit, however, that if weakening/recision of the 2nd leads/contributes to a tyrannical government, that would do more damage to the country and its people than 100 years of assault rifle ownership would.