I have to say as a "Survival Rifle" the Americans already spent a tonne of cash on this and came up with the C2 or AR7 carbine. A .22LR semi automatic that packs into its own butt stock.
If I was a Mountain Man then I'd want something with a bit more punch but this little gun will get you fed.
Simple is always good when your life depends on technology. I prefer a bolt gun in .300 Win Mag and consider it one size fits all but then it can be loaded with any .30 cal bullet and the MV adjusted further by powder quantity. It's a calibre capable of taking any creature on the planet and of shooting out to 1200 yards consistently. However for survival you are likely talking small game and a .300 isn't going to leave much.
Packing 100 rounds of .22LR vs 100 rounds .300 Win Mag isn't really something I have to do.
A .22lr or .410 shotgun are both good choices.
Sent from my iPhone using Tapatalk