Thread: 303 Query

Originally Posted by Cordite

As said above, the .303 headspaces on the rim, not the shoulder. This allowed chambers with generous shoulder space and aided mass production and also imparted some tolerance to dirty chambers under field conditions. If you are of clean habits, then just neck size and let your cases stay expanded to take up the whole chamber.

Check the case works in each rifle if you shoot more than one .303 rifle.