Funny, as they tend to be quite thicker than average in .303 Brit..
Anyhow, I use them in many calibers, and they are correct brass, not on par with Lapua, though. The main difference is the weight (the internal volume) variation which is much more than Lapua brass, more like the average variation you will find on other commercial brass. I've reloaded over 10 times with heavy loads (from a modern action) of 6.5X55 and they're still good to go.
The GRAF headstamped cases are PPU brass (Prvi, if you better like, or even, NNY (for PPU in cyrillic)). They are a really tuff company to deal with, just like Zastava, that's why they have no official importer in Canada. Century Internation Firearms used to import the PPU line in Canada a long time ago. Now Trade Ex carry almost the complete line of PPU components, under the Graf headstamp.