i purchased a jig that cut via bandsaw and it didn't work real well for me.
i think the idea of starting with your square, billets, cutting and gluing your footing and then plane the shaft round is the better way to go...however...it is labor intensive and very time consuming. unless, of course, you can afford, or have a shaft shooter or a dowel cutter. (I have the dowel cutter but it's in 3/8"...the smallest i could locate. if there is a 5/16" available i don't know where to find.)