we have AMENDMENTS so why arent they supported or followed

The 2nd amendment states that the people of America have a right to "A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed.". NOT be infringed so why are there so many gun laws. I get serial killers, but America is letting people who have been to insane asylums get guns. OUTRAGEOUS. Look at Nevada you have heard of one shooting recently and they have little to no gun laws. California on the other hand very strict and some one gets shot there every day. Help us put a stop to insane people getting guns and the perfectly fine people not get guns at all.