Identification
Search by what it is called now, what it was called then, or your best guess at the spelling. All three resolve to the same entry.
Matches
The reference
The component itself, described once and linked to every arm it appears on. This is where the identification notes live.
Also filed as “feather spring” and “battery spring” — other recorded names for Frizzen Spring. Period, regional and trade terms are all filed against the same entry, so either word finds it.
Returns the frizzen over the pan and holds it closed.
Drives the striker forward.
Tensions the sear against the tumbler.
Matched “band spring”, a recorded name for Band Springs. Period, regional and trade terms are all filed against the same entry, so either word finds it.
Retain the barrel bands in position.
Matched “main spring”, a recorded name for Mainspring. Period, regional and trade terms are all filed against the same entry, so either word finds it.
Drives the cock forward.
None of these it? Describe it to Butch — a photograph and a sentence is enough — or post it on the wanted board so a dealer can offer you one.