What happens when you run out of ammo, though? The gun is reduced to a meaningless memory. A very well made knife has so, so, so many more practical uses. The gun cannot:
Make traps which never need reloading for sustained survival over long periods of time if, God forbid, need be.
Make other weapons.
Make improvised rope for shelter, rappeling, tie-downs and traps.
Help start fires without wasting life-saving and life-giving ammunition.
Help tend to wounds and improvised sutures/ligatures.
Help tend with venomous wounds.
Fish.
Help in the process of: waste disposal, water purification, making shelter, clearing rough vegetation, and so much more.
Sure, I think any sane human being would prefer to have a gun (with a ton of ammunition), not only for hunting but also security. I know I would! But, having an extensive supply of ammo is really improbable giving the scenario we were presented with. Even if there were as few as 10 survivors out in this wilderness setting, stop and think about this -- IF there were large game in your vicinity, then, sure, 50 rounds can take a lot of game for sustained periods of time. But, if there isn't, then 50 rounds can be used up in very short order.
I also have to disagree on the trap making skills of even an inexperienced person. If, like you said, even an inexperienced person may be able to make an improvised knife, then I would think the much-easier-made traps would be just as well done by someone inexperienced. Most traps are nothing but logic put into wood then to motion.
If cave men - in small numbers - could take down several ton mammoths, then I rhink modern man could take bear and the like with spears fashioned by knives. There are methods (very relaible ones) of taking large game with improvised traps.
Actually, after having thought about this a bit more, too, I think I'd rather have a razor-edged capable tomahawk like one of Cold Steel's. (Awesome weapons by the way) They can do anything a knife can do and so much more.
Glenn, I have to hand it to you... You thought of far more uses of individual components of a firearm/ammunition than I ever would have!