I am a Mexican Lawyer and I know the federal firearms law well, here is a summary The right to own firearms is granted by the Constitution but it does not include military firearms which are according to Federal Law any firearm which can fire full auto regardless of caliber, semi auto pistols in 9mm, 38 Super and larger, 357 magnum revolvers and larger, shotguns larger than 12 gauge or with a barrel shorter than 25", rifles in caliber .223, 7.62 and 30 Caliber carbines. Legal guns to own are 380s, 38 Special revolvers, rifles up to .30 caliber (larger ones are authorized for hunting abroad)and shotguns.
Permits for the transportation and use of firearms are issued for 1 year and for up to 10 firearms for each use (hunting, shooting at your club or national competition), these permits are very easy to obtain if you belong to a shooting club. There is no legal limit as to how many firearms you can own, but once you have 10 you cannot get a permit to buy more from the only authorized dealer, you can however legally buy more from other people. There are also collectors permits which allow you to own all kinds of firearms including military ones, they are also not hard to obtain except for the fact that the military authority will inspect the location to make sure it has the necessary security measures to avoid the guns being stolen.
CCW are issued but are hard to obtain although not impossible, and if denied they can be appealed at a District Court, although few people do. Until 2002 CCW’s authorized military caliber pistols, but they were all cancelled and issued 380s.
Ammunition can be bought at certain sporting goods stores, you only need ID and a copy of the firearm registration document, limits to purchase are 500.22s, 200 center fire (rifle or pistol) and 1000 shotgun shells, these limits are per gun per month (if you own 3 shotguns you can buy 3000 shells per month).New firearms can be bought from UCAM (Sporting shotguns and rifles and Glock, Walther, Taurus, Beretta and CZ 380 pistols.
Many people carry without a license and if caught usually the gun is confiscated only with no criminal charges, and although large caliber pistols are outlawed every self respecting male in the rural areas usually owns a 38 Super.
