Buy 100 feet of each....
Here's what I run:
full comp on up to 25"...
semi skip, sometimes 25 and to 28..
full skip 28 or 32 and up.......
I do run .404 on the 3120, which normally sports 42 or 43" bars.... full skip,
Square chisel on all.... it can be hand filed or with a Silvey square...