The 8x57 CIIP pressure standards are a bit higher than SAAMI. The American standards are lower in case some knucklhead get a hold of an old .318 bore 8x57 instead of the .323 bore of the 8x57 JS.
An M98 manufactured in 1918 will have the .323 bore, and if any of the problems of a "weak" action are present, will make itself manifest through lug setback, which is easy enough to check by measuring headspace over time. Loading ammo to a lower pressure won't stop lug setback, just make it slightly slower.
Machine guns are awesome until you have to carry one.