Slight 303 confusion .

[rookie wildcat]

Won't mean anything until you measure it, somehow.

 

[bigedp51]

Well fellas, I just did a cheap head space check. I took one of my old
shells, de primed it, and re primed it in the gun. The primer is very much
flush with the rim. It is just slightly visible looking across the rim.

You cant use a fired case unless it was full length resized with the primer test, a fired case will be formed to the chamber and have "zero" head clearance.

To do the primer test and check head clearance you need a new unfired case or a case that was full length resized with the die making hard contact with the shell holder. This is to make sure the shoulder of the case is not contacting the shoulder of the chamber and the head clearance is measured from the rim.

When you use a fired case that was "fire formed" to your chamber you will have "zero" head clearance and learn nothing using the primer test for head clearance.

Below shows you how far off some of our shoulder locations are on newly made comertial non-military brass is.

Below is a surplus South African military cartridge.

So remember the military British chamber is longer than our "commercial civilian" resizing dies by the amount the case below is sticking above the Wilson case gauge. And this is why theses cases are short lived and stretch so much when full length resized. Our job as the reloader is to keep the shoulder location the same as its fired length and the case will not be able to stretch.

And when reloading the .303 British it is a good idea to have a Hornady Cartridge Case Headspace Gauge and measure your fired length and "NEVER" push the shoulder of the case back too far.

 

[budman]

My error, thanks for setting me right. Again, excellent help. Thank you.