There is no such thing as a SHTF survival battle rifle. Hes mixing too many things together here, its like rating the most dangerous fighter aircraft compared to other fighters in their era then including a list of lawn tractors to choose from.
A survival rifle is primarily for feeding yourself, it should be easily portable and self contained. Bonus points for being able to defend yourself from 2 legged and 4 legged predators because when youre simultaneously jumped by a moose and a bear you don't want to have to whip out your American Derringer Pistol. It is not a battle rifle. There is no such creature as a survival rifle chambered for .223/5.56, the 24c in .223 is a special purpose turkey gun for a group of southerners where that is legal.
The battle rifle a survivalist chooses to use for defense in a SHTF scenario might be a .223/5.56 but that is an entirely different thing, not a survival rifle. The fact that terms and things tend to get all mixed together in these w1n1 articles tends to make me think that this guy isn't just a clueless kid trying to learn from our responses, hes a FOREIGN language kid writing in English trying to learn from the rest of us.
The SR556 is the same as answering "John Deere" to the question. Its so far out in left field and sooo absolutely useless for the intended purpose as specified that it could only be seriously replied by someone not understanding the question. This is the Forest Gump answer. Not that its entirely the fault of the posters here since it is on the list and the author confused the terms/catagories.
5 rounds is really good. The M6, 24c, and x caliber are the only serious answers even really on the list and for any given target you only have one appropriate round loaded for the game in question. This isn't a battle rifle. You don't have piles of ammunition with you in a survival situation, its only the small cache that is packed with you.
These aren't my definitions. These are the definitions of the governments that are likely to have to put someone in a survival situation. Note that the US uses the M6. The Soviets developed the
TP-82, a triple barreled double 28gauge over a single 5.45x39. A drilling like the poster above suggested. Fierling configurations might be a good choice also if one could keep it light enough.
Neither of these official survival weapons are for defending against squadrons of Chinese paratroopers, thats just not what survival weapons are for. They arent even particularly useful for when the buggers swarm out of town to cause problems for those of us who live prebugged. You might be able to take out a patrol of 2 but nothing more.