Igorrock, that is indeed the cartridge. Good find the article. I'll bet those light K98K's benefitted from the addition of the muzzlebrake.

I have lost touch with that rifle. I should try to look him up and inquiry (try to aquire) that rifle. I remember it being very plain wood (Arctic Beech ???) on a FN Sporter looking action (no thumb cut, swept handle) a long-ish light barrel with a single standing rear and a bead on ramp front. I don't think it was D&T.