Thread: Resurgence of interest in the old "Three Oh"?

Greetings All,
Hatcher has an illustration of a head crack like that in his book. He found the cause to be an off center primer crimp that over hardened one side of the case head. In other words a manufacturing fault. The neck crack is from what is called season cracking. This is a natural hardening of the brass over time even in unfired cases. CAC cases, even late production sporting cases were prone to it. The case neck was likely cracked when it went in the chamber. Its my understanding that primers to all CAC military ammunition was both mercuric and corrosive. To Scout the apparent improved condition of your bore after firing cupro nickel jacketed projectiles was likely due to copper fouling (incorrectly called nickel fouling) from the jacket. This was a problem with that type of projectile only solved when jackets were changed to gilding metal. The copper needs to be cleaned out periodically with a copper solvent. Sorry about that.
Regards Grandpamac.

Originally Posted by grandpamac

Greetings All,
Hatcher has an illustration of a head crack like that in his book. He found the cause to be an off center primer crimp that over hardened one side of the case head. In other words a manufacturing fault. The neck crack is from what is called season cracking. This is a natural hardening of the brass over time even in unfired cases. CAC cases, even late production sporting cases were prone to it. The case neck was likely cracked when it went in the chamber. Its my understanding that primers to all CAC military ammunition was both mercuric and corrosive. To Scout the apparent improved condition of your bore after firing cupro nickel jacketed projectiles was likely due to copper fouling (incorrectly called nickel fouling) from the jacket. This was a problem with that type of projectile only solved when jackets were changed to gilding metal. The copper needs to be cleaned out periodically with a copper solvent. Sorry about that.
Regards Grandpamac.

Thank you kindly for that info .Seems consistent with what Ive experienced