somewhere down the road i have happened upon an fine condition copy of martin pegler's book - Sniping in the Great War - published in 2008, by Pen & Sword Military. it is a fascinating (and very well researched; including nine pages of footnotes to his sources) book that provides many insights into both the technical and human sides of the craft, as well as numerous photographs.

i have no idea about the availability of this book, but i would recommend it to any one with interest in the history of the great war.

"it's a poor sort of memory that only works backwards."
lewis carroll, Alice in Wonderland