Al- In Austrailia you have access to 215gr. bullets. Here, it's 174gr. Hornadys or 180gr. Remingtons. While they work just fine on moose and deer, black bear, many of us who actually liked the .303, liked it for the 215's. Some .303's shoot 220gr. Horandys just fine, while others don't.
; I am re-barreling a P-14 for a friend. The barrel had a .308 groove diameter, but is going to be chambered with a tight .303 reamer, spud ground to fit the .300" bore to allow .303 factory ammo in a pinch. The difference of .004 overall will make little or no difference in pressure - this we've checked out all ready. The whole reason for this chambering is to allow the use of 220 gr. Horrnady RN's.
: If doing one for myself - I'd use a slightly larger case as in the .444, or merely do the .375 Express on the .303 case, since I have so much of it.