1950s Bulgarian 7.62x25 safety alert

[ATS76]

I bought several cans of 7.62x25 in the past 2 months from Century. I noticed some are hotter than others. I opened all cans and found the following 4 head stamps:
*-10-52-3 (small quantity mixed with *-10-53-3)
*-10-53-3
10-53
10-55

I heard “*-10-52-3” is unsafe ammo and have not fired any. However, most of the “*-10-53-3” had split cases upon firing. Should I discard them?

[tlillard23]

I had the same problem with some ammo this weekend. Lot of the cases split on the crimp dimples.. I'll have to go look at the headstamp.

[EBWhite]

The split cases are no big deal at all. Does the ammo come in a pink paper wrapper? If so, with those headstamps, I'd sell the ammo. That stuff was tested and it has magnum rifle cart. pressure- it is for a submachine gun and will cause our CZ to explode.