Ok, so this has bugged me ever since the first of Forge World's (excellent) Horus Heresy books introduced Volkite weapons, specifically the Volkite Serpenta. Where does the term "Serpenta" come from? Now with the Skitarii Codex out we have other instances of the term used for pistols and it's bugging me again. I can backtrack "Caliver" and "Culverin" and even "Jezzail" to various forms of firearm with a couple seconds worth of Google-fu, but what about "Serpenta?"