Visit the Australian Army Museum of Western Australia web site
https://armymuseumwa.com.au/
Extensive glossary of British ordnance terms and technology
https://thereaderwiki.com/en/Glossary_of_British_ordnance_terms
Two customs directly related to the 15 Pounder BL gun originated at Queen Victoria’s funeral – the use of a horse drawn gun carriage to convey the coffin and the hauling of the gun carriage by naval ratings.
https://www.historyextra.com/period/victorian/queen-victoria-death-funeral-mask-cause/
Opposing artilleries during the 2nd Anglo-Boer War.
http://samilitaryhistory.org/vol022dh.html
The breech mechanism was one factor in increased rate of fire.
https://commons.wikimedia.org/wiki/File:QF_15_pounder_gun_breech_mechanism_diagrams.jpg