Exactly. The "Arab" rifles (made for Egypt and also Syria, who rejected them) were not modified in the Middle East, but by Italian factories eager for work post-war, and these rifles are problematic. Two caveats here: While the Krieghoff wartime modifications were well done, the post-war jobs were done by numerous Italian manufacturers and their workmanship , let's just say, "varied". To clear the larger round, material was ground away, and sometimes a significant amount of metal was removed from the bottom of the receiver ring. While the Carcano used very good quality steel (I've heard it said that they used an alloy developed by the Czechs)and was perfectly safe with the loads for which it was designed, the 8x57 is not a lightweight. I have seen photos of some that were so over-ground that I would consider them scrap. Krieghoff was never able to make their conversions reliable repeaters, which is why they were single-shot. I doubt that the Italian shops doing the post-war conversions would be able to do any better, and very few of them were reliable feeding. The Krieghoff's did indeed use wooden blanking blocks in the magazine well. Second caveat: While the materials are strong, I have heard it said that the Carcano design does not have great gas venting in the event of case failure. I have no first-hand knowledge on this matter, but it bears keeping in mind when examining a modified rifle before deciding to fire a heavier cartridge. I'm told surplus Balkan 8x57 can be especially unpredictable, but again, I don't shoot 8x57 so I can't speak from experience. I've had no qualms shooting the 6x54 Carcano with some brisk loads.

One last point: Just because you find an 8mm Carcano stamped "HK" doesn't mean it's genuine. Because they're worth significantly more, the Krieghoff rifles have been counterfeited. Proceed with caution.