Yep.
And there's prolly Cargo ship after Cargo ship lined up at Mexican ports with Containers full of Automatic Weapons (like real 'Machine Guns'), Rocket Launchers and Grenades. Not to mention from the 'all so honest'(/s) Mexican Military, who WE, as in US Gubmint, gave the weapons to in the first place in order to fight the 'drug war'.
The Cartels sure as heck ain't getting that stuff by straw purchases at Arizona Guns Shows or a Wally World in Waco.