My model 1898 has numbers ranging from 7 to 18 on the sliding rack of the rear sight.  I am guessing those numbers correspond to hundreds of feet when adjusting the sight for elevation.  Is that right?

Can the model 1898 sights be adjusted for windage?

What is the capacity of the magazine?

Along with the rifle, I got 14 bullets that I think are gallery rounds.  They have round balls that are almost completely seated in the case.  The cases are marked FA 5 03 or FA 6 03.  I don't have the original box.  Do these have value to collectors?  Could they be fired?  Would firing them be a bad idea?