A little more detail would surely help, but as with any older, used firearm, a general checkout by a gunsmith familiar with Ross would surely be a benefit.
If it's a Military Ross, the calibre won't be marked, but it will be .303 British.
If it's a Commercial Sporting rifle, it could be .303, .35 or perhaps .280 Ross, but WILL be marked on the barrel. I do have spare Ross rifles both Military and Commercial, available to US residents only, as well as original and re-printed Manuals. Contact me at barryj@localnet.com-Rossguy
Ross rifle was created in 1903.
Canada
In the age of the Internet a simple search with terms like "Ross Rifle" or "Ross Rifle parts" will turn up various dealers. Including your address, if you are into bricks and mortar stores to shop at will find local dealers.
ross rifle
Sir Charles Henry Augustus Frederick Lockhart Ross
Ask a gunsmith for help.
bro
Sam Hughes supported the Ross Rifle, which turned out to be faulty when used in WW1. Hughes was at the time Minister of Militia.
The Ross Rifle was used by Canadians in world war one. WW1 was mainly trench warfare and were not good conditions for the Ross rifle it would jam fairly easily and Canadian soldiers were forced to pick up dead Germans guns the Lee-Enfield
A fire involving rifles a rifle fires a projectile at very high velocity
This was a straight pull bolt action .303 rifle issued to the Canadian military starting in 1903. It had some problems. See the link below for an article on the Ross.
no it does not