I had read that the brass gets brittle over time, and storage conditions are a major player in how the stuff ends up eventually in regards to reliable primers and case condition. The Turk 8 mm is the correct type for my Yugo Mauser Model 48. The different diameter bullet that was mentioned was initially used on the 1888 Commission rifle, and then the Germans changed to the different bore, as well as a pointed bullet, and used that in their famous Mauser 1898.
I have thought about getting a Commission rifle for historical collection purposes, most of the ones I have seen are really beat up. And if there is an "S" on the reciever it is supposed to be safe to shoot with the newer ammo. I have also heard from another source that only the original type of 8 mm should be used in all 1888 Commission rifles, and Old Western Scrounger has the early type of ammo, as they make their own brass. If in doubt, do research on your 1888 rifle, and use the right ammo. The American Rifleman magazine did a recent article on that gun and said it was not reliable, so the Germans did not use it very long.
I too had a 1948 vintage Enfield #4 rifle a few years ago, one of the most accurate guns I ever owned. The feed reliability was not very good, and in Clifford Shore's book (British army sniper and instructor in WW 2) he mentioned they had problems with the clips on theirs too. Fun shooter, but I had split cases and burst primers in .303 with the old WW 2 surplus ammo as well, I mostly used the boxes of Pakistani surplus ammo dated 1960's. Sold the gun as I thought it had mechanical problems with the barrel and clip feed. That design has a notorious defect with the top hand guard moving forward and binding up on the front site, I replaced the screw and gave good torque to keep it steady on the nose cap assembly, it still would shift forward impacting the front sight with eventual repeat firing, odd how the British never fixed that goof.