You can view the page at https://www.milsurps.com/content.php...talion-C.E.F.)
You can view the page at https://www.milsurps.com/content.php...talion-C.E.F.)
I'd like to expand on boltaction's comments regarding the problems with British manufactured .303 cartridges and the Ross MkIII chambers, not the least of which was the soft brass issue which has been overshadowed by problems with the case's dimensions. According to 'The Ross Rifle Story' Lt. Col. Harkom, technical advisor to Canada's Standing Small Arms Committee, found that much of the British manufactured ammunition was made of soft brass which adhered to the chamber walls which alone added "about 30 lbs. of force necessary to withdraw the case". To that add that many Ross MkIII chambers only measured .458" at the mouth which was fully .002" smaller than the high limit variance allowed for British manufactured ammunition. Canadian made Dominion Arsenal ammunition didn't jam because only low limit ammunition was issued for service. To beat these problems Lt. Col. Harkom ordered various sizes of chambers to be reamed and found that the size that worked best was .464". Mjr. Gen. Sir Sam Hughes who witnessed Harkom's tests ordered all chambers to be reamed thusly although specially selected sniper rifles were allowed to have a .462" chamber.