Thread: 303 Query

....but 2400fps is nicer, and it's not as if .303 cases are made of gold. You should be able to load to that velocity without abusing cases by using a slow powder, etc. But if you shoot cast lead bullets, then you will be best under 2000fps.

What is more inportant than shoulder sizing is if the bolt will close on the fired case. If the shoulders are back enough to allow for this then don't worry.

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.