Reducing shafts that size is a little daunting if you've never done it before. But with a little knowledge and the right tools it's not that difficult.
I never passed up a shoot that was grossly oversize if I thought it would make an awesome arrow. Often times you can get a nice clean straight shaft from oversize shoots.
But you still want to keep the pith centered and follow all the irregularities of the shaft.
I never bothered sealing the ends of shafts. I would bundle them up, and put back for about two months. After that, I'd heat straighten w/bark on. Being over-sized, they're a little harder to straighten. With the bark on, some moisture is still trapped in the shaft, and this makes straightening much easier as the steam makes the shaft more pliable.
Best way I've found to make a BIG round into a LITTLE round is to first square it up. From there you can knock off the corners and then scrap/sand to desired weight.
