Split in the neck of the brass

[bars full auto]

Went to shoot my Turk Mauser today and found a split in three of the brass casings after I fired a round. This isn't the best pict in the world, but if you look closely you can see a split in the casing.
http://wsphotofews.excite.com/028/Pf/oK/V7/eo83280.jpg

Do you think this is caused by bad headspacing or 1947 vintage Turk ammo. As allways thanks for the help.

[Richard Simmons]

It's the brass. The "47" has been posted about on a lot of the boards. Bad year for brass evidently as it seems to have become brittle with age. I've got some "49" that has been great.