Mmmh, depends on what is to be chopped. On stationary targets (anything that doesn't move or bend out of the way) an axe or hatchet will easily outperform even a big knife. I have directly compared a wetterlings hatchet against an RD9 which are amost the same length and weight and on stationary targets the RD9 doesn't stand a chance, that is with an edge thinned to 15 deg. (just under 20 deg on the Wetterlings). The Wetterlings hatchet will take down any of the pictured trees in shorter time but far more importantly with much few strokes. If you were to take the Wetterlings Hunters axe, the difference would be so large that a comparison wouldn't make much sense anymore. The Wetterlings will run you between $20 and $30 compared to about $120 for most of the large knives and $400+ for the large Busses. And after chopping a few trees they will also continue to shave easily. However, the fit and finish (or lack thereof) of the Wetterlings will require that you even out the grind on a coarse stone and sharpen them up properly.
However, on everthing that is not stationary, in particular branches up to 1" of very hard wood and 2" of soft wood (pine) a big knife will out perform any axe. The tip speed is much higher and you can clear a branch with one swipe. Of course you can often put the branch onto chopping block and use an axe but a knife can clear the branch "free standing" which is usually much more efficient. But for that the knife needs to be of decent length. I would agree on 9" minimum. Of course in a pinch even a 7" knife can chop but very quickly batoning becomes far more efficient.
As a rule of thumb I would say, on everything that needs only one or two fast swipes the knife wins, on anything bigger the axe wins with each additional stroke you have to take the axe becoming more and more favored. On a 2x4 (not exactly wilderness survival
but a good example) a knife might seemingly even outperform an axe, because you can take more strokes with a knife than with an axe in the same time, and you might chop through a 2x4 quicker with a knife even though you will need fewer strokes with the axe. However, on ten 2x4s fatigue will set in and the axe will first pass the knife and eventually pull far ahead.
Just my $0.02 as usual.
P.S.:Why do you guys make such rediculusly small v-notches when chopping? Very inefficient!
