Re: trying to figure out what rifle this is.
It's a Mauser 88 "Commission Rifle" NOT a k98, NOT a mannlicher-schoener, Not a mannlicher-steyr.
FWIW, none of those rifles are the same thing.
I have at least 1 of each except for the M-Schoener. Whomever posted the differences in the 8mm ammo is correct, DO NOT shoot 8x57 Mauser commercial ammo in it.
You need to use light loads with 318 bullets or it's going come apart in a hurry.