Here is the link to my latest research report on one of the earliest predecessors of petronel stocks on long guns; those long guns were aimed held firmly in front of the arquebusier's chest, with one hand firmly grabbing the downcurved buttstock: a short Landsknecht/mercenay's matchlock aquebus of ca.1520-1530, with an older brass/'bronze' barrel from ca. 1490-1510 re-used:
http://www.vikingsword.com/vb/showth...+arquebus+1520
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