Like any other military force, cartels are run by their supply chain. As such they use whatever is the most plentiful and easiest to procure and supply ammo for in their area of operations.
E.g, cartels in a middle east/European scenario will most often be using surplus Russian military gear and ammunition, central/south America will rely more on NATO and US calibers imported south, Africa will use a smattering of both European and Russian calibers depending on the local colonial influence, east Asia will be dominated by Chinese and Japanese specs (themselves also often derived from Russian designs). And almost everywhere you will find Russian equipment, they made and sold so so fucking much of it.
Since they are more clandestine that government forces they overwhelmingly rely on small caliber arms that can be concealed and shipped. Not too many mounted machine guns except in very large centralized operations.
Like any other military force, cartels are run by their supply chain. As such they use whatever is the most plentiful and easiest to procure and supply ammo for in their area of operations.
E.g, cartels in a middle east/European scenario will most often be using surplus Russian military gear and ammunition, central/south America will rely more on NATO and US calibers imported south, Africa will use a smattering of both European and Russian calibers depending on the local colonial influence, east Asia will be dominated by Chinese and Japanese specs (themselves also often derived from Russian designs). And almost everywhere you will find Russian equipment, they made and sold so so fucking much of it.
Since they are more clandestine that government forces they overwhelmingly rely on small caliber arms that can be concealed and shipped. Not too many mounted machine guns except in very large centralized operations.