With a barrel marked 8.1, l'm sure it could handle either 7.92 or 8.2 mm bullets. Simply a question of which gives the best accuracy. I expect the S bullets to shoot tighter groups in an 8.1mm barrel. Any doubts about pressure, have the neck area of the chamber reamed to S specs. It most likely already is. When converting 7.92 mil rifles to fire the then new 8.2 mm S bullets, the only mod to existing rifles, was done to the neck, to allow for slightly greater expansion, for quicker release of the projectile. This fact is well covered in literature relating to the 8x57 and 8x60 in their transitional phase.