I am looking to put the basic components for a catapult in my pocket survival tin. what are the best materials to use for the "pulley"part : rubber bands,rubber tubing,elastic? has anyone got any suggestions or other ideas.

latex surgical tubing is OK, but could be better. I haven't played with anything else. The tubing isn't very thick, but I wouldn't put in on the inside. Instead, I'd tie it off around the outside over my tape (same way they do for a blood draw *shudder*), as an extra layer of water resistance. It does need to be replaced, just like the water bag/condom in the PSK. <br><br>It's actually not bad stuff to have around, as it CAN be used for a restricting band (snake bite), for splinting, or about anything else you need a strong elestic for. And since it's tubular, you can use it to suck water out of seeps. Hmmm.... Gonna have to scrounge some from my EMS friends.<br><br>For a bigger pack, like a 72- or 120-pack, a folding Marksman slingshot might be worth it, and definantly a LOT better than anything you could improvise int he firled, both for power and accuracy.. But all things being equal, laws willing, I'd rather slip in a Browning Buckmark or a S&W "kit gun" and a box of hot 22s into that volume. Better for hunting for the pot than a slingshot, IMO.

With a PSK there are space limitations so it is necessary to think "within the box". A sling-shot is available by using the latex tubing already mentioned by Cyberraven. Also the wide rubber band mentioned as a waterproofing solution could be used. Get an inner tube from a bike shop for a fat tire (mountain bike) and slice a 1 inch width section out of it. This can be used around the tin in the place of the electrical tape (or in addition to it) and will work admirably for a sling-shot. The double advantage of the tubing is that it can be used to suck water from a seep as was already mentioned or to siphon other fluids as needed. The double advantage of the rubber band is that even if it breaks during usage you can fashion an ancient style sling-shot from the remaing pieces and the twine / fishing line / paracord / sewing thread already in your kit. Of course this style of sling can be every pit as accurate as a catapult type (after approximately 6 months of daily training ;-)) I imagine that even the condom could be used as an elastic for a catapult if you double it over. Not going to get much range but it could work.

i would think that the space would be more wisely invested in with just more paracord, its multipurpose and can be used to fassion an old-time sling. if this is your intended purpose i would recommend practice and you can buy a sling shot pouch that would work quite nicely to hold the ammo for the sling.

You could try just throwing rocks or make a throwing stick. With practice that could be just as effective.

Weellll.....<br><br>Just as devils' advocate, in open country, a sling probably works great, but when I've tried learning to use one, I always end up getting them tangled in brush and tree limbs. Also isn't any where near as easy to use to a slingshot.<br><br>Then again, my first rule on survial gear is "Can I use it in shock, one handed, while hypothermic and my knee dilocated again?" I'm not picky