Get caught and it is 5 years for one live .22LR or one live 12 gauge shotgun round. Up to 30 years or more for any "military" caliber. Roll dice. Take chance. They grab your car, boat or RV too. Complete forfeit.
We had a guy come north one time, all his crap had been seized by the Mexican Customs. He was screaming at us to do something about it. We looked at him and said, dude, be glad they let you come back North. It could have been a lot worse.
Anyone who complains about cops up here has never dealt with the Mexican Police. Good Lord, the aftermath I've seen of stupid college kids who mouthed off down south.