When I look on some of the target shooting websites I see that some categorise sight fittings into 2 categories for Anschutz Rifles, < 1913, 1913+.

Please could someone explain the difference?

I have a Match 54 Action and would like to add a sight raiser/extender like this:

http://www.edinkillie.co.uk/ecatalog...der-p-919.html