Contact the seller and ask him. He wrote the ad and has the gun in hand so would be the best source of information. You give no context as how the word is used so it is impossible to offer a guess that might shed light on the matter. As you mention, it could have something to do with a choke manufacturer, or gun model, or firearm manufacturer, or time period, or it could be auto-correct changing one word for another. Contacting the seller is your best bet.
