Don't shoot that thing with modern ammo! Slug the bore, make sure of the diameter. You may know this already, but it confuses folks. The original 88s were a round nose and .318" diameter, 8x57J. The updated Spitzer for the 98 is a .323" bullet and would be a problem in a .318" bore, let alone they're a little hotter and the 88's gas handling system isn't up to the 98 if a case blows, let alone any other damage.
I've fired mine with surplus, has a .323" bore barrel on it. But, I download handloads for it now if I feel like shooting it. It's been sitting for 25 years unfired, though. I keep it just because. It's a neat old gun and you ain't SEEEEEEN a smooth bolt throw even in modern high dollar hunting rifles compared to this thing. Open the bolt and slightly tilt the muzzle and it just slides open on its own, old world craftsmanship.