Ross headstamps

Can someone tell me how many different Ross Rifle Company headstamps there were and what years the company produced ammo. Thanks.

I have some articles, that contain some conjecture, so no guarantees!
The 303 Ross model 1912 MATCH CARTRIDGE , year of manufacture 1912, headstamp 303 BRITISH. [O.A.L. 3.422 INCHES]

The 303 Ross model 1913 MATCH CARTRIDGE, [longer more pointed projectile] year of manufacture 1913, headstamp R. R. CO. [ O.A.L. 3.656 inches ]
There is a round in existence that originated from the Ross collection
headstamped R. R. CO. 15 V11, BUT there is a belief that this round was made up at the later date just for the collection.

April 1, 1921 issue of The Rifleman’s magazine outlines the reason for these rounds, " the 1912 PALMA match" and the 1913 Pan American and international rifle matches at Camp Perry.

The U.S. won the 1912 match but only just by a few points, but soundly beat the Canadians in 1913, so you can draw your own conclusions as to weather Ross persisted with his match experimental 303’s for a further 2 years.

Hope this is of some help, but I have never seen the definitive word on these rounds, always fact mixed with conjecture.

The Cartridge Headstamp Guide has four Ross Rifle Co headstamps illustrated:

R.R.Co. . 280 ROSS .
R.R.Co. 15 VII (.303 Brit)
R.R.Co. CAN. VII 14 (.303 Brit)
R.R.Co. CAN. .280 ROSS.

Guy, Your right, I was only thinking only of the MATCH cartridges, and not the 280 ROSS cartridges made by Sir Charles Ross.
But 303 BRITISH should be there, as it is the headstamp on the 1912 Ross 303 match round.

Thanks to Terry and Guy. This is the info I was after.