The oversize bore/groove .303 Brit are certainly out there. I have an original 1895 Winchester .303 British made in 1910 that has a groove diameter of .317” I shoot 8mm “I” bore .318” bullets and have a Corbin swage die to reduce standard .323” 8mm if necessary. - Mike
-------------------- "Will Rogers never met a fighter pilot"
- Anon
“Always carry a flask of whiskey in case of snakebite, and furthermore always carry a small snake."
-- W. C. Fields
My #4 has a .315" groove diameter with it's 2 groove barrel. I re-chambered it to shoot Ken Water's .312 Express round. With that ctg. and 174gr. .312" Hornady RN's, I drive using Re#19 at 2,964fps, it makes 1 1/2" 3-shot groups at 100 meters with it's iron sights (rear peep and front blade).
-------------------- Daryl
"a gun without hammers is like a Spaniel without ears" King George V