Hi Don, I have asked this muley/sash saw mark question too. The link helps to explain. A modern portable bandsaw leaves a smoother cut than the old up and down saws. It's saw pattern is regular but can vary with the feed rate. Tooth set is key to how fine the cut is, if there is a tooth off it takes only one to leave a consistent drag mark for every revolution of the band. It wouldn't be irregular unless the operator was irregular and even than it would be a gradual change. I run my mill at a slower rate and on a 12" wide board there is a 1" space between the drag marks. On narrow stock you can push it to 2"+. I am wondering it the up and down saws have an angle to the drag mark, place a square on the board and see if it is true of off. I am going to check my band cut stuff.

Here in Machias there was a large 10" or 12" wide band saw in operation through the early 1900's. Search " from stump to ship" I will with more time, got to run. Tim