Unrotated Projectile
Unrotated Projectile is an artillery gun or artillery model.
Overview
Short range anti-aircraft rocket, developed for the Royal Navy.
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
“Unrotated Projectile”, English Wikipedia, consulted as further reading
Consult the sourcereference work · Reputable secondary · Wikidata
Wikidata, structured authority record Q2645623: Unrotated Projectile
Consult the source