Very few bears carry Kalshnikovs....Seriously, the AK-47, shoots a round known as the 7.62x39mm. With apologies to all those who have been killed by one, it is not an extremely effective killing machine. The developer of the carbine, General Kalashnikov, once stated in an interview that the cartridge was designed to wound rather than kill. He figured that a dead combatant could lay there till the engagement was over or he decomposed, whichever came first. A wounded combatant yells and screams for a medic, and can take several other combatants away from offensive firing to drag the victim to a medic, a mobile care facility, or at least a less exposed location. The Russians figured that severely wounding a high number of the enemy troops was a greater logistical hindrance to him than fatalities. The carbine is also extremely easy to build in russia, or replicate in third world countries with rather primitive tools, is easy to field strip and repair in poor conditions, and is very tolerant of dirt, debris and poor maintenance (unlike the M-16, which is fussy as a Ferrari). It also shoots like crap, and is not extremely accurate. The approach is called "spray and pray", and volume makes up for accuracy. The Russians themselves didn't use it for sniper or precise fire work, but substituted their Dragunov bolt action rifle.
My point is that I'd not trust one to stop a bear. They work better on humans, who tend to be more compliant after receiving a serious wound than predators, who tend to get even nastier. If a long gun is desired, I'd opt for a more powerful caliber, say a .308 in a short mountain rifle, or even an old 30-30 lever action carbine. Those are fairly cheap second hand, and ammo is also cheap, and they are easy to handle and fairly light. They have fast target acquisition with iron sites. (Scopes are slow...used to target critters who don't know you are there, not charging animals in close.
There have been a number of bear attacks in AZ over the years; notably in the Chiricahuas, Catalinas, and along the Black River on the San Carlos Reservation. Almost all were in camping areas with vehicular access, which means, food, garbage, and bears who had lost their fear of humans due to feeding and/or poor sanitation practices. Rustler Park at the north end of the Chiricahua W.A. has had a long history of bears getting into cars attracted by Coolers, food and yes, Beer). I'm not aware of any attacks in truly remote wilderness areas of Az.
A rash of attacks in Canada by black bears yielded the data that the carcasses of the offending bears were all in "ketosis"; which indicates that the bears were malnourished due to disruption of habitat or closed acess to previously accessible food sources. The attacks were all predatory, rather than protective of young, or the result of surprise encounters. Grizzly attacks are usually the latter, which raises the question of which subspecies is really the more dangerous. I'd still vote for Bro. Griz, since there are few hand held firearms capable of an immediate knockdown. -R