Handbook for 4" Marks VII and VIII Breech-loading Guns
My copy of this document is a black and white photocopy of an original at TNA. Most of the plates were in color, but I do not have the benefit of seeing it. My copy lacks a title page and starts right at the table of contents. Perhaps I misfiled it but I seem to recall them saying that it was missing in the original. Also, I seem to have missed getting images of plates 40 through 46 (noted in red below).
LIST OF PLATES
I do not have copies of those shown in red
One important background note on naval weapons, and in particular the Royal Navy's weapons of this period, is that small guns like this are often discussed as systems comprised of a gun (which is simply the barrel and breech mechanisms) and a mounting upon which it sits. The RN nomenclature system details guns by the diameter of their bore and a "Mark" designation of a roman numeral. Small changes in a design sometimes do not merit a new Mark number, but are instead denoted by appending stars (asterisks) , e.g.: Mark VII**. Mountings are usually denoted by a roman numeral after a "P.", which may stand for "pedestal", for such is what these man-worked weapon mounts were called. Mountings may also have stars in their designation.
For instance, on the "I" class destroyers, the 4" guns were accurately identified as 4" B.L. Mark VIII guns on P. V mountings. The B.L. is short for breech-loading, and is itself a loaded term if you'll excuse that phrasing. All guns of this period were loaded at the breech, but a distinction was made between those guns which had a self-contained projectile which combined its powder load with the projectile itself and those which separated the projectile and the powder. B.L. guns were the latter type, and the powder was rammed into the gun breech after the projectile in silk bags. Q.F., or quick-fire guns were the ones with "bullet-type" ammunition, with an integral brass case containing the propellant.