The First Amendment is highly curtailed compared to the second. You can't cry "fire" in a crowded theater. You can't print slander. Yet you can't require a license to buy a gun. You can require a license to shoot a deer, but you can't require a license to buy the thing to shoot the deer with. You can proscribe the places you can fire the gun, but you can't limit the access to them in any way to citizens in good standing. I had to pass a test to ride a motorcycle. If I wanted an AR-15, I'll bet I could pass that license, too.
You can't cry "fire" in a crowded theater. You can't print slander.
Well, you can, there are just consequences for those actions. Consequences which also regulate the use of firearms, you can't fire a gun in theater, and you can't shoot at someone you hate. but you can't limit the access to them in any way to citizens in good standing.
Further regulation and licensing wouldn't prohibit those in good standing from obtaining even if they had mal-intent. This is why the argument for repeal of 2nd A is stronger than further regulation. However, the philosophical implications of a repeal are huge and would fundamentally alter all aspects of law and life in America.