Sorry for talking dirty, but Epps says using a .308 barrel for the 303 Epps chamber works fine without pressure problems. I have shot .308 180s in my #1mkIII and chronographed them to be 100 ft/sec slower than the Sierra .311 180s. There was only a slight POI change at 100 yds of an inch lower and about a half inch right.
I wondered if they bumped a bit, but doubted it as the bullets are harder than lead, which shoot best for me in that rifle at .313,wheel weight and tempered. I have not shot that for years now.
Ingwe, those were great pictures of that Lee Enfield in Africa.
Randy