Loading for a Ross

I have a 1905 Mk ll***, one of the ones sent to the U.S., and would like to work up some loads for it. I have seen some references in old posts that the bore on these is smaller than .311 and someone referred to them as a "tight .30 ". I have both .308 and .311 jacketed bullets ( both 180 gr.) and gas checked cast in 187 gr .312 and 180 gr. .309 on hand and have IMR 3031,4064, 4895 and Red Dot powder. Can anyone clear up the bore size for me and does anyone have a pet load based on the bullets and powder I have on hand?
thanks

Ross rifles made pre 1911 have a bore .298-.299" and groove of .309". In 1911 the bore size was changed to .303" and .311" groove.Your II*** probably has the tight bore.

Absolutely forget the Red Dot! You could slug the bore and determine its exact size, but in all likelihood it has the standard tight bore. You could use any load recommended in a recognized loading manual using your bullets and the other three powders, assuming that the rifle is sound. You might want to experiment to determine what load gives you the best accuracy.