Several companies.
No way of telling without knowing what make and model the rifle is, what condition it's in, and what country it was manufactured in.
yes there is a springfield .303 i have one from 1942 its a springfield rifle with a .303 british barrell
number5 mark 1 enfield 303 british jungle carbine
yes it is just a difreint mesherment 303 is british and 7.7 is jap.
British 303
Yes, how ever they were not the original manufacturers the originals.
Combination of serial number and features.
50-300 or so
No, a 303 is a rimmed cartridge, the 308 is rimless.
7.7x56R, more commonly sold as the .303 British.
Up to the 1950s, it was the British Enfield 303 caliber rifle.
$50 to over $1000. You didn't give any specifics to help narrow it down. All we know is that it's a rifle in .303 British service... presumably, it's probably going to be a Short Magazine Lee Enfield, but we don't know the specific model, what country it was manufactured in (SMLEs were manufactured in many countries), or even if it is an SMLE.. it could be a Lee-Metford, it could be an Enfield Pattern 14 rifle, for all we know, it could even be a Canadian-made Ross rifle.