SBML Two-Inch Mortar
SBML Two-Inch Mortar is a 50 mm mortar or artillery model.
Also recorded as Ordnance SBML 2-inch mortar; 2-inch mortar; two-inch mortar; 2 inch mortar; 50 mm mortar SBML.
Overview
1930s portable 50 mm mortar of British origin.
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
“Two-inch mortar”, English Wikipedia, consulted as further reading
Consult the sourcereference work · Reputable secondary · Wikidata
Wikidata, structured authority record Q652388: SBML Two-Inch Mortar
Consult the source