more than likely, it is a BPE gun.
The weight should help you figure it out.
Below 4kg it is a BPE, over 5kg is probably a NE.
Yet another option would be a NFB, somewhere in between.
If I understand right, only a .303 would be marked "NITRO PROVED" in that time frame.
WC-

Last edited by WildCattle; 02/16/15 03:10 AM.