Chainsaw Repair

Well during my trip here in Wyoming I had a chance to cut up some cotton wood that was 33" inches across.   So I used my Poulan 3700 60cc, my Poulan 395 64cc, and my Jonsered 670 67cc.  All three saws had 20 inch bars and 3/8ths chain.   The 3700 had a chain that I square ground, the 395 had a chain that I hand filed square, and the 670 had a new Oregon chisel chain.   Well to my surprise the 3700 was cutting faster than the other two.   I really thought that I had done a better job on the hand filed chain but I do not think it was any better than the Oregon round ground chisel on the jonsered.   I was having some tuning problems with the Jonsered and I think it will do better once I get that fixed, but still I was surprised.   The only draw back with the square ground chisel was I barely hit the ground one time and it went from making chips to sawdust in nothing flat.   When I get back home I will be converting more of my chains to the square ground.   No doubt I am hooked now.