Hi Kuduae,

Thanks for the info, I'll look out for the books.
The 416 only has the one serial number which I sent away to Paul at J Roberts & Son Gunmakers in London (which were most helpful) and he came back with a manufacture date of 1956.
I'm a bit reluctant to take out the mag well as it's in there nice and tight.
Here's some pic's of 416

Cheers