The US has a rich history of adding and abolishing amendments.
That is the next DC debate.

He did not have tracers. The Gun Store was out of stock.

The Vegas hotels are used to allowing people to bring dozens of guns and ammo into their lobbies and rooms. Vegas is famous for having gun shows that sell guns privately without any regulations about 2 to 3 times a month. Vegas gun shows are considered entertainment and are as common as dirt. There are 2 major gun shows that are continuous and some minor ones outside the strip.

Hotels are happy to oblige.