Ive had no problem breaking down pistols shotguns rifles and such on the bed of the tailgate in the HD parking lot. If a seller acts weird about it I walk away. Even If something is a major issue most manufacturers will remedy for little or nothing. Ive sent stuff to Ruger, Springfield and...
I would work under the assumption that anything sold here that's used is "as-is." Caveat Emptor. As as seller i wouldn't warranty anything for functionality or to operate safely. Not because I would try to scew someone but you can never underestimate the idiots out there messing with firearms...