Well the Springfield M6 survival rifle was offered in 22LR and .223... I originally wanted more punch/kick for the buck until I calculated the price and commoness of one vs the other. I chose 22LR because of what you said in terms of ammo weight. If used correctly 22LR will be as effective and versatile as .223. Don;t get me wrong... I would love to have 30-06 and 12 gauge combined in something that weights as much as M6 but that's impossible.
But in regards to the book. I still believe that he was totally unprepared and his skills and abilities didn't match his ego. And his luck run out.
Matt