Being a .303, I would assume that it is a military weapon, correct? Was it made before January 1, 1899 (that means 1898 or earlier) or is it post 1898 manufacture? I am also going to assume it is a bolt action, and not some sort of full auto or something, would I be safe in that assumption?
Scenarios:
1. Modern (Post 1898 military surplus weapon), that is legal for civilian ownership:
The firearm must be imported by a licensed importer. Only C&R mils-surps are okay for importation (50 years or older OR on the list), and it needs to be dcumented that they were in the couintry that it is coming from for at least 5 years.
2. Antique
If it is an antique rifle, you can have it shipped right to your door, but this is only doable if it is verifiably antique (ie Serial Number matches the range made before 1 JAN 1899) , or it is stamped with a pre-1899 date, or the model was discontinued before 1899.