Sorry guys, but the .303 is actually bigger then the .308.
The .303 (7.7x57Rmm) use a .311/312 bullet (same as the Arisaka (7.7x58mm) and Mosin Nagant (7.62x54Rmm) and SKS/AK (7.62x39mm)) whereas the .308 (7.62x51mm) or .30/06 (7.62x63mm) uses the .308/7.62mm bullet...The Mauser used a 7.92x57mm.
SMLE makers:
Great Britain-- Royal Small Arms Factory in Enfield and at seven other (and differently marked) plants.
Canada--Longbranch Arsenal
Australia--Lithgow Arsenal
India--Ishapore Arsenal
USA--Savage Arms only during WW2 and ALL marked "US Property".
Pakistan--Pakistan Ordnance Factories
They were never made in Turkey.
Country: United Kingdom
Markings-------Factory
Enfield -- Royal Small Arms Factory Enfield
Sparkbrook -- Royal Small Arms Factory (Sparkbrook)
BSA Co -- The Birmingham Small Arms Company Limited
LSA Co -- London Small Arms Co. Ltd
ROF (F) -- Royal Ordnance Factory (Fazakerley)
ROF (M) -- Royal Ordnance Factory (Maltby)
B -- The Birmingham Small Arms Company Limited
M47C -- Birmingham Small Arms Factory (Shirley)
Other Countries
Longbranch -- Canada
Lithgow -- Australia
GRI -- British India
RFI -- India (Post-Independence)
US PROPERTY
-- Savage Arms U.S.
POF -- Pakistan
Sources:
Skennerton, Ian.....The Lee-Enfield Story.
Arms & Militaria Press. (1993) ISBN 1-85367-138-X.
Hogg, Ian V.....The Complete Illustrated Encyclopedia of the World's Firearms
A&W Publishers (1978) ISBN 978-0-89479-031-7.
You want additional info on your SMLE then try the Surplus Rifle Forum
http://www.surplusrifle.com/
Are you getting Indian FMJ as they still produce some but for the most part mil-surp ammo is a dead issue...All you can do is buy factory stuff or the brass.