(facepalm)
Why would you ever need to put anything firearm related into a PP transaction description? It's not as if the payment descriptor will allow you some kind of proveable documentation if there's a dispute. If that happens, since it's firearms-related, you're screwed with PP's dispute resolution service anyway. Your only recourse is through the EE, or whatever website or auction site you used, or the local police if they're interested in non-payers/non-senders of small Internet transactions.
And yes, PP will close an account for saying "trigger"
And IMO PP isn't really that anti-gun, just hugey invested in their CYA mentality. They're living in fear the next "Columbine Kids" will put together "fully-semi-automatic assult pump shotguns" from "parts" bought over the internet and have 60 Minutes and 20/20 camped out in their corporate eBay lobby demanding an interview.
They don't really care if you use PP for firearms, parts, or accessories. They just want plausible deniability for themselves.