QF 12 pounder 18 cwt gun
QF 12 pounder 18 cwt gun is a naval artillery or quick-firing gun.
Overview
British naval/coastal defence artillery.
In detail
It is associated with United Kingdom of Great Britain and Ireland.
Sources
Each source is named with the standing the house places on it, so the evidence can be weighed rather than taken on trust.
reference work · Reputable secondary · Wikipedia
“QF 12-pounder 18 cwt naval gun”, English Wikipedia, consulted as further reading
Consult the sourcereference work · Reputable secondary · Wikidata
Wikidata, structured authority record Q2121197: QF 12 pounder 18 cwt gun
Consult the source