As so many specimens are dug up in Great Britain we may safely suppose that in the Cromwellian Age, the caps of wooden powder holders on English musketeers bandeliers were often made of lead, certainly due to the moist weather on the island.
The term 'powder cap' used in some desriptions on the site linked here is not quite correct of course; actually they are not caps for powder but for powder holders or measures.
http://finds.org.uk/database/search/...objecttype/cap
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