Fred C, before you start reaming on the .311 barrel, read about the 1917 barrels in Hatcher's Notebook.  The decision to standardize P-14 parts for US 1917 production included leaving the .303 barrels in production and simply chambering them for the Springfield case. 

A 1917 with an original barrel should shoot .311 bullets more accurately than they ever shot .308 bullets.  That is why they shoot so well with cast bullets.

WW2 2-groove barrels shoot OK because they only have half as many places for sloppy work.  Often the 4-groove barrels have 2 pairs of grooves of differing diameters.

The .276 Enfield cartridge was just a bit smaller than the .280 Ross.  That is why the 1914-1917 action is so big.