Was thinking about getting the cheaper on to square up logs for turning on layth. I've watched Utube video's don't see why they wouldn't if you got good saw and keep it in tip top shape (ensure chain sharp and getting enough oil to the chain to prevent overheating). If you get one let us know how it works at the end of your post

I had the exact same plan--turn windthrown timber into lumber. I purchased the Granberg mill from Bailey's sizing it to my 32" bar. I have a Stihl 660 powerhead. Thus far the largest thing that I have cut has been approx. 24" or a tad larger. This setup works fairly well but can be slow going when cutting the full width of the log. I would prefer having the larger 880 powerhead but the significant increase in price was more than I wanted to invest. My total investment thus far with saw and mill has been about $1200. I bought ripping chain from Bailey's. It looks pretty similar to chisel chain with different edge geometry but it does give a smoother cut surface.

You will want to have plenty of time to cut your logs. Even with a big powerhead your progress is slow. The saw gets very thirsty when ripping. I can get about 20 linear feet of cut out of a tank of gas. That's OK, as it is also about when I have to stop to sharpen. Its really not that big of a deal. By quickly removing a stabilizing bar on the mill you can sharpen the chain without removing the mill. The touch up and re-fuel takes about ten minutes. Since you're just doing a few trees per year the speed at which you process any one log hopefully won't matter all that much.

I am not familiar with your saw so I don't know how well it will handle a 30" oak. The Granberg company sells various options to speed the process when handling large trees, like double ended bars for instance, in case you want to run with two power heads simultaneously. I recommend that you buy the smallest rig that will meet your needs. It all gets more expensive and harder for one person to operate as the mill gets larger.

Not having to bring the logs out of the woods is a big asset. Even a two inch slab is all I want to handle. Making sure that the bark is clean, or better yet--removing it, will allow more cut between sharpenings. The mill is very portable. Remember however that you must have a guide rigid enough to give you a straight cut at the start. I made one out of 2x lumber that allows me to cut logs up to ten feet long.

I looked at several portable mills on-line before buying and in the end decided on the Alaska mill. I am doing much the same that you describe and have been pretty satisfied with my purchase. Incidently, I am cutting trees that have been down a couple of years and I seem to have to treat my fresh cuts for powder post beetles. I'm trying to keep them from migrating out of the sapwood and into the heartwood.

tpat, thanks for your insight. Are you using .375 or .404? I would think that .375 chain would cut faster and leave a little more lumber behind, but probably dull and wear out faster, too.

My 6401 would only get as much power as your 660 if I upgraded, but I might hold off on any mods to my saw until after I find out how it rips.

I was thinking about getting the 36" Granberg kit for only $209 from Bailey's, but I need a longer bar and a ripping chain. I also would like the aluminum guide rails. The $629 complete kit with an auxiliary oiler looks attractive even though rails are not included. I need to measure the trees to find out what I can get away with.

I'm using .375. I bought my ripping chains from Bailey's. I think that it was the Carlson brand. I also have the 36" Granberg, although I would have to buy a larger bar to use the full length of the mill. I didn't worry about the auxiliary oiler and thus far the chain seems adequately lubricated, but I'm only cutting logs about 24" in diameter. I've never used the rails--always just rigged something out of 2x lumber. I've been told that an old ladder will work as a guide rail as well.

OK I am moving closer to buying a mill and could use help deciding on a size.

I measured two oaks that came down last fall. Both are about 21" DBH, much thicker at the ground. These trees are representative of the size of trees that come down a lot. The measurements are without removing bark, which I should do to remove all the sand...more tools to buy I guess.

The Granberg mills come in 24" (max cut of 20", requiring a 26" bar) or 30" (max 26", 32" bar). My Makita 6401 at present is at the low end of Granberg's recommended size to run a mill, and going larger on the mill means it will be harder to cut smaller stuff.

So, should I get the 24" setup for now so I can cut up to 20" (bark removed) and get a larger mill & big-bore kit for the saw later on if it works out? Thanks.

You can't have too much power for ripping. Even juiced, your 6401 is going to be marginal on the smaller mill. tpat's MS660 is a 92cc brute.
As far as chain goes, conventional cross cut will work fine unless you desire a smoother finish. Then ripping chain is the way to go.

I'll go with the smaller setup and see how it goes. No doubt a larger saw would be good but in my two saws I currently have less than $400 invested. Picking up another even larger saw is not in the plans at present.