Loaded up some 330gr 50 Beo ammo last weekend using Alexander Arms load data. Cycled fine and was pretty accurate but upon inspection I noticed discoloring down one side of the brass like powder blow by? Whats up?
Pressure can be high enough to cycle the action but not high enough to expand the brass and make a good seal in the chamber. Assuming that you aren't using max load data you can try increasing the charge until you get the results you want.