Thanks, ssj.
I should really splash out and get a good barrel for this gun. I shall be fire-lapping it to see if it will shoot straight as it is. It was a 'sporterized' one with a steel clip on front sight thing to make it look 'sporty'. But the bayonet bearing portion of the barrel was chopped off, much to my chagrin. Do guns have to be completely unmodified to be allowed?
There are no distinctive markings I can see on the barrel. Just the usual barrel specs and a crown with BNP under it on both barrel and receiver ring. It is five groove and the sight has the thumb screw on top.