[1] The Ross Mk.II (or "model 1905") rifle was highly successful in target shooting before World War I, but the close chamber tolerances, lack of primary extraction and length made the Mk.III (or "1910") Ross rifle unsuitable for the conditions of trench warfare, exacerbated by the often poor quality ammunition issued.

[2] By 1916, the rifle had been withdrawn from front line service but continued to be used by many snipers of the Canadian Expeditionary Force until the end of the war due to its exceptional accuracy.

[clarification needed] Sir Charles Ross offered to finance the construction of a factory in Canada to produce his newly designed straight-pull rifle for Canadian service.

The bolt handle and sleeve thus need only be pushed backwards or forwards to open or close the action of the rifle.

The single motion required to open or close the bolt of a straight-pull-action rifle is theoretically faster and easier for soldiers to learn, thus perhaps offering a higher rate of fire.

Unlike the Lee–Enfield, the bolt of the Ross rifle could be taken apart without special tools, although this was not necessarily an advantage as it encouraged unauthorized disassembly by soldiers.

[citation needed] The rifle showed poor tolerance of dirt when used in field conditions, particularly the screw threads operating the bolt lugs, jamming the weapon open or closed; it also had problems when British-made ammunition was used, which was produced with lower tolerances than Canadian-made ammunition.

"[8] Complaints rapidly reached the rifle's chief sponsor, the Canadian Minister of Militia and Defence Sam Hughes.

He nevertheless continued to believe in its strengths despite the professional opinion of Sir Edwin Alderson, the British Army officer who was commander of the First Canadian Division.

[12] By the time of the Somme battles of July 1916, Sir Douglas Haig, the new Commander-in-Chief of the British Expeditionary Force, had ordered the replacement of all Ross rifles in the three Canadian Divisions by the Pattern 1914 Enfield, which was finally available in quantity.

In November 1916, Hughes resigned after Sir Robert Borden's decision to appoint a Minister of Overseas Forces.

Many weapons would have this replaced with the Sight, Ross Mk II, a curved sliding "Lange Vizier" type.

The original sliding button safety and the magazine cut-off were retained, along with the 28 inch barrel and the stylish older rear hand-guard.

In 1911, the shorter variants were replaced by the longer Rifle, Ross Mk II** as standard Canadian issue.

The 28 inch barrel, stylish rear hand-guard, sliding button safety, and magazine cut-off were retained.

A new rear sight designated the "Ross Battle Aperture" was installed on the bridge of the receiver rather than on top of the barrel.

[1][2] Because of its long range accuracy, the Ross rifle continued in use among Allied snipers after it was withdrawn from normal front-line use in Europe.

British snipers found the rifle accurate out to 600 yards and more, with only one inherent disadvantage: the Ross accepted only perfectly clean ammunition, totally free of mud and grit, or else it invariably jammed.

Five hundred rifles were fitted with 5.2× Warner & Swasey Company Model 1913 prismatic telescopic sights manufactured in Cleveland, Ohio.

By the same time, he made a commercial agreement with the famous gunmaker firm Charles William Lancaster, inventor of the oval bore, to be his exclusive UK agent.

In November 1906, Ross while in the process of developing a new and very powerful .280 caliber sporting cartridge, made some experimental tests with a necked-down version of the new .30-06 Springfield case which he called the .28-1906 (one rifle is known to exist).

The new high-pressure round required some strengthening of the bolt and action receiver, but the rifle was otherwise only slightly different from the .303 Mark II.

[citation needed] The new .280 Ross cartridge gained it a fine reputation for medium-sized game, and for a time after 1918 it was a fairly common rifle on safari.

[citation needed] Ross Mark II** Commercial Target Model in .303 British, with a 30+1⁄2 inches (770 mm) heavy barrel, was a real success in the Match Ranges from 1908 to 1913.

[11] After the First World War, the British Empire supplied several models of .303 cal rifles, including Rosses to Estonia, Latvia and White Russian anti-communist forces.

In the 1930s Stalin approved aid shipments to the Spanish Civil War Republicans, disposals actually, of American Winchester Muskets, German Mauser 98s, British Lee Enfields, Austrian Mannlichers, and several French types.

The Mark 3 Ross rifle was supplied to the Royal Canadian Navy, the Veteran's Guard of Canada, coastal defence units, training depots, the British Home Guard, Metropolitan Police, London Fire Brigade, Port of London Authority Police and the Soviets.

Ross Rifles were collected hurriedly from stocks held in the Shetland Islands in May 1942 to re-equip the survivors of Operation Fritham in Spitsbergen who had lost everything when their ship was sunk.

The Ross rifles and equipment being delivered by Catalina 210/P captained by Flying Officer Tim Healy.

During the World Shooting Championships in Moscow, visiting shooters were allowed to sign for Ross rifles converted to 7.62x54R to try out the competitions.