No. 4 Mark I splits cases

[Adam Helmer]

Joe,

Your problem IS: the reloads WERE NOT SHOT PREVIOUSLY IN that new #4. I have many .303 rifles in various Marks and ALL are different. In my reloading die box is a list of "-1/4 turn, -1/2 turn and one is -1.5 turns " on the resizing die.

When I acquire a new .303, I load NEW .303 cases with a mild charge of Unique powder and a cast bullet to gently Fire Form the cases for THAT rifle. At the bench, I set the sizing die to get just a slight "crunch fit" and I get 10 or 12 reloads with identified .303 brass before the primer pockets get too loose.

Hope this helps. If you find a source of #4 bolt heads, please post it here.

Adam