I had the very rifle you mention, but it started ut as a .358 Norma Mag. For several years I shot the .358- hunting, and with cast bullets in competition 3-position shooting at 100 yd. With 250 Speers it was amazingly accurate, well under 1/2MOA with a 12X scope for winning turkey shoots, but at 2,900fps, they were a bit soft for Moose and Elk.
: In 1975 I rebarreled it with an original .375 M602 barrel. The sight lugs came top-dead-centre and it headspaced perfectly- an amazing feat - or plum lucky.
: This is a heavy rifle, going almost 11 lb. with scope, (11 lb. even in .358 mag) but what a beautiful shooting rifle it was. The recoil was soft and with 6 rounds in the magazine, express-type sights and a flip-up peep, all aspects came together to make tight shooting easy.
: It-too was exceptionally accurate with all .375 bullets available at that time, including exceptional accuracy with cast bullets for plinking.
: That is what I know of the ZKK602BRNO.