The Wiki reference you mentioned does include .308, but I'm still not convinced on the 8mm Mauser chambering...which is what the OP originally asked about.
Without pics, there's no way to know.
Many m/1894 carbines and m/1896 rifles were successfully converted by Carl Gustafs and Norma into the CG 63 Competition Rifle chambered in 6.5x55mm and 7.62x51mm NATO. These rifles are known to be very accurate, with heavy free-floating barrels, diopter sights (many models), target stocks and tuned triggers.
Natch, anyone could put an 8mm Mauser chambered barrel on one, my question is whether that was actually done by Gustaf's, as a "factory" CG-63 build.