Could be 22 mini mag HP...Not something I’d want to be hit with. Even a standard 22 round is quite lethal.
I’d bet a cup of coffee someone in the company or maybe the truck drivers are connected to one gangs/cartels. Maybe that’s why the drivers were released alive.
If you were going to a gang shoot out or a cartel hit, would you pick a .22 as your weapon? I can’t see this going to gangs. The cartel might very well have connections to a “legitimate” large retailer somewhere in the hemisphere. Sell the whole thing .40 on the dollar.
The problem with 22s is not that they don’t kill you, it’s that they don’t kill you fast enough.