There are several factors that could be in play here and you could try to eliminate them. You have already done the first thing I would have suggested in regards to the barrel band and free float. If you have access to anyone who has a 10/22 factory barrel that is know to be a decent shooter you could try to borrow it and see what the difference is in your groups to determine if your factory barrel is the issue. Another issue could be the bolt its self in respect to the bolt face and head space. Another option would be to place the entire unit into another stock and see what the results are. No sense wasting money on the barreled action if there is issue in the stock. What about barrel fit to action? Is it sloppy or loose?
That's a good point about barrel fit, my 10/22 saw an improvement in accuracy when I replaced the v-block with a new one from Rimfire Technologies.
