Both the bow and sling are as easy to master, for one main reason: the bow allows repetition, but you tire after tens of shots while the sling isn't as easy to repeat the exact same motions with but you can practice so many more shots with it, and most anywhere. As a survival weapon - only if you've spent time getting good with it. As with bowhunting, spearing, and other ilk, you need good stalking skills as well. If you work on your accuracy, then birds would be good game for this. However, other methods should be worked on first, as using a sling can expend a lot of energy that you might not be wise to spend yet. One reason I carry three slings with me in my emergency pouch is that they're fun to play with, roll up small, weigh nothing, and have multiple survival and emergency use. For example, I can untie the thongs and use them for snares, lashings, tourniquets, fishing, and so on as well as a sling.
I use both bow and sling, so think I can compare the two somewhat. I think that a raw beginner, with no knowledge other than that from watching movies, and with a serious interest in mastering both would find both to be of the same difficulty. The reason I say this is that the arrow is a little more stable, and the bow is quite easily applicable to repetition. That is, I can pick up the bow, put my feet just so, hold the bow just so, draw to an anchor point just so, align the target against the bow just so, and shoot. But I can only shoot so many times before I get tired, and the minute I get tired, my aim and form will suffer. Now with the sling, it is not an easily repeated situation but the ammo is more plentiful and the areas where you can shoot are far more plentiful and you can carry the sling with you all the time and so shoot whenever you have a moment free and a good site. With the bow is the ease of repetition, with the sling is the abundance of practice.
If one had to learn alone, just pick up the equipment and try to work it out, then I'd say the beginner would have better luck with the bow, at least at first, simply because of the ease of repetition. The difficulty of the sling lies primarily with not being able to recall as accurately as with the bow exactly where your hand was, what angle your wrist was at, how fast you were slinging, where was your arm, etc., etc., when you release the stone. This is without anyone to provide comments, assistance, or instruction, as if you were out in the middle of the plains all by yourself, the nearest town 100 miles away and there on the ground lie a bow, arrows, and a sling.
Bill Blohm
bblohm@boi.hp.com