Mikey,
You are 100% correct.
The transition from large calibre blackpowder cartridge rifles to small bore smokeless rifles and ammunition was a rapid one.
From the late 1880's to the turn of the 20th century, every major (and minor) military power that had the resources went to 6.5mm, 7mm, .30, .303, or 8mm military rifles and ammunition.
Large caliber black powder rifles were issued to second-line (mostly colonial troops) well into WWI and the 1920's, mostly by the British, French, German, Dutch, Italians, and Russians. The "colonials" used these until the 1940's, '50's and '60s, until they were sold off to the North American market as surplus. What is available today are the much-sought-after military BPCR that shooters want.
Umfan1, If you want a classic BPCR suplus military rifle, please get into the waiting line with the rest of us! *GRIN*
John
John