I doubt that. How about providing an estimate of the total number of rounds fired by criminals in Kalifornia last year? Was it even a thousand? Two thousand?
I would be surprised if Kalifornia's criminals used more ammunition last year than I have in my house. Ammunition will never be scarce to criminals.
Actually, there is plenty of video proof, and actual arrests, of Mexican citizens buying cases of ammo in the US to take back to Mexico. Ammo from the US makes sense because the cost difference between the US and foreign sources is not enough to make up for the shipping and convenience. Additionally ammo is not like a fully automatic weapon. Just about anything they want is readily available.
It’s not like they can just but it in Mexico.