Personally (and this does NOT come from experience) if you are in a survival situation and do now need a chopper, I feel anything from 5-7 inches would work out best. It is large enough to cut up fairly good sized sticks of wood and it will also be easier to skin out and clean fish and other critters you are fixin for the pot. And if you are attempting to make eating utensils and traps and such it will also allow for easier work along these lines as well.

Just my two cents based on watching all the great ones, specially the greatest, Bear! grin wink

(personally though, I prefer my water from a stream or river). grin

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