I wrote a bit about Mexican Gun Laws in this thread:
International law or protocol

There are also references to Mexican Gun Laws in this thread, if you have time for reading through a rather short thread that never deviates from it's central topic. Well, just a bit.
Penultimate Pre Postwar Magnum is in Mexico!

The long answer to your question about "How hard is it to get the necessary permisos to own and shoot your guns in Mexico?" is; It depends.

- Are you Mexican? (If so, that helps a lot and will just make it hard to find a gun, any gun, which may or may not be a decent gun, and get it registered, join a Club that can actually do the paperwork and then get a permiso to take it shooting when you want.)

- We'll assume you're not Mexican, but speak pretty derned good Spanish and have lived in Mexico for more than 5 years and pretty much know the ropes. (If so, that helps a lot and will just make it derned hard to find a gun -- any gun, which may or may not be a decent gun -- and get it registered, join a Club that can actually do the paperwork and then get a permiso to take it shooting when you want.)

- Or let's assume you're an "fresh off the boat" North American or European who doesn't speak Spanish, is fairly clueless about how things work down here and you want a gun. This is the category where the vast majority of North Americans/Europeans who are looking for guns these days that I run across fall into.

No lie, no B.S.; those people are basically screwed. To paraphrase the last James Bond movie, they are basically "kites in a hurricane".

Mexico has no gun stores, except one run by the Army in Mexico City that is actually closer to a midievel torture studio moved up to the modern era. It doesn't matter how hard you try, you'll never get it right. Once you get them all the paperwork they want, then they'll want the original copy of your wife's mother's birth certificate "for their records". The answer "well that doesn't exist anymore" is not the right answer. I went throught the process when I bought my Glock from them in 2001 (a process that started in 1999) and would not wish it on anybody. Oh, well, another dream shattered. But I did get my Glock when I realized that if I couldn't come up with the documents, I had to come up with the documents. Photoshop was new then, but I'm not sure what I did would work now.

So there are no gun stores except one that won't sell to you until you've jumped through all their hoops. Good luck with that. That leaves the "Black Market". We come back to the question; how good is your Spanish? Or another question; how well do the people who sell guns down here on a regular basis know you and trust you? If the answer to the first question wasn't "real, real good" then there's almost no chance that the answer to the second question will be positive.

So there's no guns stores (that work properly) and all the guns on the Black Market are controlled by the ... well ... Black Market. You need to understand that the Mexican Gun World is a closed society. It has to be to survive, the laws are draconian and often politically interpreted. There are no Gun Shows. There is no advertising allowed, except that which is available through the Mexican Firearms Internet Websites like Mexico Armado or En la Mira. No "Want Ads" in the newspaper. No guns at garage sales (that would be a ticket to jail).

I will not waste your time telling you all the ways a person "fresh off the boat" doesn't qualify to find himself or herself a gun that's decent and get the permit for it within a calendar year. Or five. What will work would be basically, any Mexican Club is made up of about 5 - 20 "core" members who are putting on all the events and trying to build up the Club while the rest of the society around them trys to destroy it or minimalize their efforts. If you get in with them, and they decide to help you, you'll come out okay. Those are the guys (and more rarely girls) that everyone in town and the surrounding area (from Police, Military, and Rurales and Federales, etc.) know are in the Club and either don't bother them or generally don't look too closely at. They are the ones that will find you a gun if one becomes available and help you with the paperwork and legaleaze. The Club may have 200 members, but it's those "core" guys who actually pull all the weight. Anyone else is a hanger-on.

Mexico has had a rough time the last 8 years or so. Crime has been high, and even when it was fairly normal any little incidents were blown up so well by the press that it seemed a lot worse than it was. I know, I was here. I have a list on my office wall of North Americans and Europeans who are "looking for a gun". That list only grows, it never gets smaller because the simple fact is; there aren't a lot of guns around that are for sale. When one does come up, it's either an illegal caliber or a piece of garbage, generally. ANYTHING good that comes up is going to be offerred to my other friends in that "core group" that runs the Club and believe-you-me, one of them is going to buy it. Also, the guys and girls in the "core group" tend to sell guns to each-other, rarely outside the group and even if they are selling something half-desirable and nobody wants it, they'll offer it first to the "core group" of a neighbouring club. It's a closed society and it's hard to get into it.

So failing all that, for the person "straight off the boat" the only option is a Hi-Point for 1,000.00 dollars or an RG .38 Special for about 800.00 dollars (it's only missing the center-pin!). The Club guys don't buy the junk. They don't "buy and sell" the junk. You need to go ask around with the Mariachi's in the center of town, who, ever since that movie came out, some of them are selling the cheap guns nobody else would want out of guitar cases for atrocious prices. In Canada, or the U.S., the law is the law is the law. Here, there's the written law...and then there's what they're going to do with it. Throwing money at someone who can decide for-or-against you may (or may not) help. Giving him a bottle of nice Tequila on the sly would probably work better. Or showing up with someone he already knows who's willing to vouch for you would work best of all, and be the cheapest by far and probably good for cementing decent future relations. None of this is easy for the "fresh off the boaters..." and it won't become easier in the future unless the laws change. A lot. Which I don't see happening down here although it would be nice as long as they change for the better.

So I guess the short answer would have been; "No, it's not easy." Since I've done my time and gotten myself into the Mexican Shooting Community quite well, my opinion is same as the old man said at the end of The Wild Bunch; "It ain't what it used to be...but it'll do."