Phaedrus,
I don't mean to diss your friend, but even allegedly experienced old timers sometimes give bogus advice. (For example there are still people around who will tell you to drink whiskey in cold weather to keep warm.) In my opinion your friend was giving you very bad advice.

The virtually unamimous advice from bear hunting guides, biologists, and others with experience shooting bears is that if you choose to carry a firearm for bear protection you should:
1. Try to avoid getting in situations where you need to shoot.
2. Carry the most powerful gun you can shoot very well.
3. Practice until you are extremely proficient with that gun!
4. Select heavy solid bullets with good penetration.
5. If you must shoot, shoot to kill.
6. If you wound a bear, you must follow it into the brush and make sure it is dead.

Back in 1983 the USFS in SE Alaska did a study to determine the most appropriate firearms for USFS employess to carry for bear protection. That study needs to be updated, since there are many more gun and bullet options now, but the basic recommendations are still valid.

Bear hunting guides sometimes have to go into the "pucker brush" to finish off a bear wounded by a client. Some have been known to carry the 458 Winchester Magnum. The 375 H & H Magnum and the 338 Winchester Magnum are popular bear hunting rifles. The minimum rifle that most would recommend for bear protection would be a 30-06 with heavy bullets (220 gr).

A 12 gauge pump shotgun with an 18 inch barrel, loaded with rifled slugs, is also a good choice for bear protection. These guns have good penetration, are fast to bring into action, point well, and can be fired rapidly. (Note however that buckshot is not considered a good ammo choice by knowledgable persons.)

Handguns are severly lacking in power (relative to rifles and 12 gauge), but are easier to carry and can be fast to bring into action. If you opt for a handgun for bear protection a 44 Magnum with hot loaded solids is the minimum. However, in my experience, many people carrying 44 Mags don't practice nearly enough with them and aren't skilled enough with big handguns to rely on them for bear protection. In my opinion, many of those folks would be better served by carrying a 12 gauge with slugs.