4.7 inch QF Mk IX,XII gun
4.7 inch QF Mk IX,XII gun is a quick-firing gun or 4.7 inch gun.
Overview
British naval artillery.
In detail
It is associated with United Kingdom.
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 4.7-inch Mk IX & XII naval gun”, English Wikipedia, consulted as further reading
Consult the sourcereference work · Reputable secondary · Wikidata
Wikidata, structured authority record Q2121203: 4.7 inch QF Mk IX,XII gun
Consult the source