I am having .303 surplus military ammo problems, I have set the head space so I know it is correct. The ammo does not stick in the chamber and extracts fine. So...............my problem is the military brass splits and cracks at the shoulder ranging toward the mouth of the case they all do it. The factory Remington fires just fine with no showing of any slits or cracks.
The military is markedRG9-6-53 on the box further markings are M*7 ISAA 32 cartridges to the box. Headstamp is RG 52 (l OR 7)
Is there an answer? is the military brass weaker?

I know you downunder guys (blokes) shoot more of the .303 than I do.