Jack Stevens
AH enthusiast
FYI, the 600s in .350RM all had vented ribs on the barrel (unless modified by the owner).Ive got a Rem 600 in .308 that I absolutely love... would be over the moon if I could find one of the 600's in .350 Rem Mag that doesn't have the rib at a reasonable price.. they are super little carbines!
Sounds like the one you want is the M600’s successor, the model 660.