Three ways:
1. Buy it from the Army store, jumping through all the hoops they make you jump through and accepting the limited stock of decent revolvers they might have. If they are out of stock when you are suddenly approved to buy, that's your problem. Apply again, jump through more hoops...
2. Buy it on the black market. Then go register it at your local Army base. If it's not a "prohibited weapon" (over .38 Special or .380 acp in caliber) there should be no problem other than just a few hoops to jump through.
3. Buy it from someone who already has registered it and is selling it. Good luck with that, though. If it's any sort of decent revolver or firearm and it's already registered you will pay through the nose for it. Buying a "registered gun" just means changing the paperwork, and you don't need to take the gun in to the authorities. A Glock 25 from the Army Store costs about 8,500.00 pesos, or about 680.00 dollars. Buying one that is already registered costs somewhere around 18,000.00 pesos (around 1,450.00 dolloars) and it's surprising how many people pay it because they want to avoid the potentially extreme hassles one can run into dealing with the Army Store.
Here's the true scoop: if your Spanish is good and you are patient, you'll be fine but you will jump through hoops. If your Spanish is not good, then find a friend who speaks fluent Spanish and get his help, and you'll still be okay. Otherwise, be patient, smile a lot and hope for the best. Being rude, uppity or lippin' off to the Mexican Army would be a bad move. I can think of dumber things to do, but they're all suicidal.
Our Club charges people a fee to help them through this nightmare and if a prospective member is actually joining the club and going to help the club out then the fee is pretty small. The general rule of thumb is: "if the person is asking what they can do for the Club, they're fine. If they're asking what the Club is going to do for them, they're on their own."
Can you bring down a revolver from the U.S. or Canada? Practically speaking, "no". Have I done it? I refuse to comment. Do I know people who have done it? Yes, but I refuse to comment. To put it bluntly it would cost you more than most revolvers are worth and the people you will have to deal with to get this done are perhaps not people you'll want to deal with. Discussing people like this, let me assure you nobody will "middleman" that for you except for even more money -- and then if they like what you're importing it will be stolen anyway and you'll be out the cash.
But there's lots of good older stuff down here. Until 1972 there was no draconian gun-law in Mexico. Anything that was here before 1972 is probably still here. There's lots of nice 27's and 28's being used to make "Model 23's" out of. I even saw one done up from what was once a Model 24 I think because it had the pinched frame with no top-strap checkering but top-strap grooving.
I hope this answers your question. Getting solid answers to simple questions in Mexico is difficult because often the true answer is: "it depends."
It depends on who you know, who you are, where you are, why you want to, and who owes you a favor. Money is involved as well, but with the right connections the money is always less. Without the right connections the money is always more and in no way a guarantee in any case. Mexico does not move in black and white, Mexico moves in shades of color as well as darker shades of grey.
Years ago, back in Canada, sitting on the tarmac waiting for the plane to take us up so we could jump out of it, a young fellow doing his first jump asked me if his parachute would open. "Of course it will," I told him. "Besides, what are you worried about? I'm older than you and I'm going up. Go back to your group, you'll be fine."
He smiled and walked back to his group. A friend sitting beside me with his own parachute on said quietly when the young man was out of earshot: "Unless, of course, it doesn't open."
We all chuckled. But when he jumped it did open, and he was fine. But Mexico is like that. People who don't like that sort of constant uncertainty usually don't like living here despite the weather.
