Have owned or have shot just about all of the survival guns...my thoughts:
AR7...Have had two of the original Armalite guns and still have one. If ones eyes are half way decent shooting something the size of a clay bird at 60 yards is no problem. They can be scoped but then can not be packed down into the stock. Easy to stow in a backpack, canoe or airplane. Mine have been very accurate and reliable. If reliability is not good it can usually be traced to the magazine/chamber interface. There are several companies who manufacture these, some good, some not so good. I use mine usually on canoe trips.
CharterArms Explorer II (pistol) with scope...very accurate at 50 yards...
Savage 24...have owned four, .22LR/.410, (2) .22 Magnum/20 ga. and a Camper Model .22LR/20 ga. In addition I have shot friends .357 Maximum/20 ga. and a .30-30/20 ga. For a pure survival weapon the very compact Camper model with 20" barrels was very accurate and easy to shoot flying targets with the 20 ga. barrel. I sold it only because I like the .22 Magnum/20 ga. more and still have those two. With a scope both guns shoot under 1/2" at 50 yards. Buskshot and birdshot patterns are excellent...slug accuracy with everything I've tried sucks. One of the Magnums with a Tenite stock is my truck gun...
Marlin Papoose...probably the best one for the money out there today, especially the stainless. I have shot two, both accurate and reliable. One of the new stainless guns is on my want list and may put a pistol scope out on the barrel.
Browning/Norinco Takedown..the old classic is very accurate and reliable. Don't bother mounting a scope on the receiver as it will not hold zero....that is why they now have the barrel mount. I've had one Browning, an older one with the grooved receiver and two Norinco's with the barrel scope mount. All were very accurate. The Browning and one Norinco functioned flawlessly one was very very ammo picky.
FI Bronco...these 70s vintage guns were all metal, even the stocks. They were a swivel breech design in .22 LR, .410 and an .22LR/.410. Very hard to find. Have shot a .410 and own a .22. A little hard to shoot with the open style rear sight but more accurate than a handgun for most people.
M6 Scout...looked at them all my life thinking how "neat" they were. Had a friend who bought a Springfield Armory in .22 LR/.410 and converted it to a Hornet...never did shoot his. About 7 years ago found a pristine SA pre-triggerguard M6 at a local auction house for $150.00 so gave it a try....after extensive testing I would rather have a sharp stick. It is the only .22 rifle I ever owned that I could outshoot myself with any .22 handgun I own..at any distance. Ergonomics sucked. Trigger pull and the unusual placement sucked. Sights sucked. I am sorry to be SO negative on something so revered in some survival circles but I sincerely wonder if any of these guys spend any time outdoors. Cord wrapping the barrels can both change the POI and once it gets wet will rust the bluing right off the barrels. .410 shot did have effective patterns but buckshot scattered and accuracy with slugs was poor and came nowhere close to where the sights were. Some of the later guns manufactured by CZ for SA could also mount a scope but that then takes all the compactness out of it. Many I have seen had red dot sights on them...have these people never heard of battery failure? And the chinese junk they mount on them also fail. Again I am sorry to be so negative on this gun but it is simply the worst thing I have ever owned.
Remington Nylon series....although not a takedown it is a very rugged, accurate and reliable rifle. Don't bother with a scope as the cover shifts and POI will not hold.
Cricket/Chipmunk....very accurate and reliable. I have an all stainless one in .22 Magnum.... Super lightweight and compact. easily taken down into two parts. Excellent peepsights with rugged course front sight.
Stock is hollow and will hold a lot of "stuff"...
Marlin 39...excellent guns especially the compact 16.5" Takedown Model.
Rossi Pumps (can't remember the model numbers). Easy takedown, very reliable and accurate. B-Square makes scope mount that replaces the rear sight for a scout scope. The little 16.5" carbine would make a nice backpack gun. I had one, sold it and currently have one in .22 Magnum.
YMMV...Bob