There are no grizzlies in New Mexico. Frankly the average black bear in NM is about 250 pounds. You might wonder around most of your life and not find one over 300 pounds. The skin is thin and they aren't hard to kill. I would frankly encourage the buyer to carry a revolver. As long as he makes a point to get used to it doesn't really matter if it's a single action or a double action. I've carried a Single action for years and they just point well for me, but he may feel more comfortable with a double action. There are a ton of guns that would work. When I lived in Alaska for 33 years I mostly carried Buffalo Bore ammo. Most people have to get used to it.
A good 357 magnum, with 180 grain cast bullets, a 44 Special/mag that you can shoot MacKays good 44 Specials would be great. 45 Colt is always a good choice there just aren't quite as many guns to choose from in double action. His 270 grain hard cast should give you a lot of confidence.
If your friend is willing to spend the time to get used to a semi-auto, and the things that can go wrong you've gotten a lot of ideas that will work. Frankly I'm not a Glock guy, but DeFlave's Glock recommendation, well a guy could do worse. 180 grain bullets should work well. This may seem like heresy but I don't consider a 1911 as the ideal gun for a novice. I like the 3rd Generation Smith's and consider them to be exceptional. He should carry as a minimum a mid size, to full size semi, and forget the Mini's that are so popular for concealed carry these days. Obviously a good holster, I like the Guides Choice from Diamond D. It's out of the way for casting and higher to stay out of the water.
Nice of you to help your friend out. Spend plenty of time, shoot plenty, and make sure he can handle what ever his choice is, readily and is competent.
Something else your friend needs to understand. Bear spray works with black bears to a certain extent, but should he find himself in a position he needs to use the spray on a black bear, it's time to vacate the area. If the black bear is predatory they will be back. It's time to go somewhere else.
