Splitting cases.

[tycoonbob]

At a recent trip to my local indoor shooting range, I fired my NAA 22 mag mini revolver about 15 times.  About a third of the cases split.  This has never happened in the past.  These were Winchester Super X 22 mag jacketed  hollow points.  Any idea what caused this?

[G50AE]

Welcome to the forum tycoonbob.  Do you still have the factory ammo boxes?  These usually contain the batch information from the manufacturer.

[OLD and GRUMPY]

Another user had this problem with win mag and his mini. He posted pictures a few months back. Think it was Super X. Contact Winchester they need to know. 

I have empty .22 brass from the 50s and 60s. It feels thicker than new stuff. Some cheap stuff is little more than foil.