big bars and 325 chain
I would like to add to my previous posting, that a bar fitted with 325 that is any longer than 50 inches does tend to stretch the chains some, 325 chain works best at 50 inches, if you use longer bars, one must be very gentle on the uptake of the throttle smoothly does it, once you are in the timber a fixed throttle is a must, I never use the hand throttle once I'm into the log, this gives a much smoother passage through the log, it you are going to use the hand throttle, then I would apt for 3/8, but never 404 because its just too wasteful, especially in a nice walnut log.
Adjusting the correct angle of cuter is another way to minimise stress on your chain, this is the norm for freshly cut logs, but a log that has been standing for several months needs and even steeper angle for cutting hardwoods, I have used zero degrees in the past on hardwood logs, oiling or cooling is the other most important senario, if the chain is too hot it will stretch what ever the chain size or type is being used.
I sometimes fit a secondary cooling water feed for cuting logs that have been standing for more than six months, this makes a big diference, if you use any of the water soluable type oils you can obtain wherever you reside, it emusifies and cools everything very nicely.
The mention of weighting the mill against the timber is not needed, if you fit a side roller to the mill, this works by letting the chain pull the mill in tight against the log and guides the whole rig along with relative ease, saving valuable strength and time, there is no point in letting the mill being slammed against the log and trying to wrestle with it to advance along the edge of the board, let the side roller do all the work not yourself, then you will have little to no bouncing of the mill against the log each time you try to slide/advance sideways.
Picture is of my side roller fitted directly below the risier post of the mill.
Raily