Thread: .303 loads

Originally Posted by TeRei

http://www.ranchdogoutdoors.com/Fire...tish_cases.jpg

This illustrates the problem

Greetings @TeRei,
I fished out some of my old military ammo and none look like the SAAMI spec case but more like the fired cases and the fired cases from my two rifles. A cartridge drawing from a Pet Loads article however shows a case with a long sloping shoulder like the SAAMI case. Handloading was not even thought of in the design of the .303 case which headspaces on the rim and not the shoulder. All it had to do was chamber and fire with the empty case being ejected into the mud. To get around the problems I neck size only with a Lee Loader and keep the loads light. Fired cases often chamber without sizing or are FL sized just enough to chamber and neck sized thereafter.
Regards Grandpamac.

Originally Posted by grandpamac

Greetings @TeRei,
I fished out some of my old military ammo and none look like the SAAMI spec case but more like the fired cases and the fired cases from my two rifles. A cartridge drawing from a Pet Loads article however shows a case with a long sloping shoulder like the SAAMI case. Handloading was not even thought of in the design of the .303 case which headspaces on the rim and not the shoulder. All it had to do was chamber and fire with the empty case being ejected into the mud. To get around the problems I neck size only with a Lee Loader and keep the loads light. Fired cases often chamber without sizing or are FL sized just enough to chamber and neck sized thereafter.
Regards Grandpamac.

Greetings again,
This has fascinated me a bit so I dug out a couple of cases from my scrap bucket that had shoulders that looked much the same. One was full length sized in my Lyman die from around 1970. This flattened the shoulder a little but not as much as in your picture. I looked up both the CIP and SAAMI case drawings and they were about the same. One thing I did note was that the shoulder angle for the chamber is about 3 degrees steeper than the case. This means when the case is sized the shoulder body junction is moved back slightly with the neck shoulder junction being left in about the same place. The shoulder head space is also increased slightly. Why this was done I have no idea.
Regards Grandpamac.