I picked up this rifle the other day and am gearing up to load it. Looking at using either the Lee 457-340 or 457-405. I'm leaning towards the 340 because it could double for a heavy 45 Colt mold. planning on forming brass from 50-90 using 8mm Lebel to form the shoulder and 45 Colt on the neck.
The rear sight is different than other Beaumont's I've seen. The sight flips up for ranges over 600 yards, under that it slides up a ramp and is clamped in place with a knurled nut.