.303 M-10s?

[NORTHOF60]

I'm not an expert on the Ross, but my understanding is as follows:

The basic Ross rifle action manufactured after 1910 was the M-1910. This action was revised and issued around 1913/14 as the M-10. This coincided with the revised bolt stop. The factory sporter categories for the M-1910/M-10 were R (basic - no checkering, with Winchester barrel mounted step adjustable sight, and single stack metal magazine), E (better stock wood with checkering, barrel mounted flip sight, and single stack metal magazine), and M (top of the line, barrel mounted sight, blind magazine). I've seen the sporter category stamped at the knox form of the rifles. The .280 Ross sporter was not stamped because it was always a M. M-1910/M-10 factory sporters always had the sight mounted on the barrel, with the exception of the M which could be equipped with an auxiliary Porter pop-up peep sight on the action "bridge". Factory sporters never had the the military receiver bridge sight.