My apologies, after reading the above postings and Sons very polite "Ed you have a few loose screws" I searched every Enfield book and manual I have and they all say the inner band screw should be tightened until it bottoms out but be free to move up and down.
(Moral of story, NEVER ever argue with Ian Skennertonicon or Son the Ozmanic) BUT the Australians do cheat at Yacht racing, Rugby and Soccer.

Ian Skennerton
Small Arms Identification Series No.1
.303 Rifle, No.1 SMLE Marks III & III*

ASSEMBLY.
"Inner Band: Spring should have slight play when screw is tightened up.
(Test with pressure with large screwdriver)"