Hi Farmer,
About the .311" sizing. I usually size my .30-30 stuff .310" but had temporarily lost the sizer so put in a .311" one, made up a few dummy rounds & gave it a go. I figured maybe the neck would be too big or bulge or something like that but none of the 50 rounds showed any sign of that so loaded & shot them. All these were fired cases that had been trimmed back to 2.028" so maybe the necks were thinner. If the bullet slides into a just fired unsized case, thats a pretty good indication to me that they will work out OK. Of course, each rifle is different but they work in my '94 Black Shadow & a Stevens 325 that I just picked up. I also wondered about sizing them down from .314" like you said but they slid right thru. These were just straight wheelweight metal. Perhaps something harder might have given me trouble. I use the Lee sizer too so maybe that makes a difference. I ran some Saeco 150 gr. flatnosers thru one time tho & they did give me trouble as they were hardened & about .314" coming out of the mould.
I would stick with .310" but just for the record, the .311" sizing didn't cause me any grief. Seems a little big tho..