It could very well be referring to bullets in the "pew! pew! pew!" sense.
I'd recommend The Military Revolution by Geoffrey Parker[1] if you're curious to know more about the transition from knights to guns and all the strategic ramifications.
Ah, I'd been thinking it must be a device somehow related to manufacturing bullets (but how? was the question) -- it hadn't occurred to me that it could mean the pointy tips of bullets themselves. And thank you for the book recommendation.
Something's off here - bullet shaped bullets didn't appear until 1820 or so, musket balls preceeded .. but this is an excavation of a 14th century workspace with pre ballistic armor.
I'm tempted to think "bullet points" is either something lost in translation OR (it happens) a transcribed into text NOTE that indicated the list should have been made as bullet points.