Mj 1943 mvii

Took the No. 4 Mark II out this Sunday for the first time...box of winchester, box of PPU and box of surplus....winchester and PPU cases looked fine after firing...the surplus-not so much....marked MJ (australian) 1943 MVII
took a round apart with the kinetic puller when I got home -pics shown...
Guess this stuff is a wee bit old to be firing! (Although..it did fire and group just like the commercial rounds)
Probably going to pull the rest of it and use projectiles for reloading.

Nothing wrong with the cases doing that, the necks are just a bit brittle when formed back in the day. Remember the case shoulders and neck were formed once loaded with cordite.

I have fired Commonwealth surplus since the early 1980s, and I saw that one cases back around 1982, they would occasionally show a neck crack and or a split right at the shoulder, especially on WWII surplus, but I have seen it on RL54, GB55 and RG from 1954 to 1956 headstamps.