Post some pics of the case heads. They might be crimped mildly and you not notice.
Try hitting them with a crimp reamer, uniformer, or swager. Run your expander/decapping pin down some so you can really feel the spent primer getting pushed out, see if they're difficult to remove.
I suppose if you're lucky they just have tight pockets and should last longer. If that's the case, and not crimped, I'd reach for the swaging tool.
What's the lot number? I have some norma .223 55gr that's a LC lot. I think they're rebranding a lot of bulk offerings these days. IIRC I had some of the tactical packaged line of 22lr which was RWS headstamped. It was good stuff, not quite up to the price they wanted verse CCI SV, but reasonable. I don't think norma would waste their time making bulk .308 either.