rolling block
rolling block is a breechloader or firearm action.
Overview
Firearm action, subclass of breech loader.
In detail
rolling block is a breechloader or firearm action.
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
“Rolling block”, English Wikipedia, consulted as further reading
Consult the sourcereference work · Reputable secondary · Wikidata
Wikidata, structured authority record Q4217947: rolling block
Consult the source