Can't speak for this model in particular, but this is just splitting hairs. Some non exposed hammer pumps can be closed uncocked same as you close a bolter uncocked. Worth a try, better than storing with a spent case in it, at least for long term storage in high humidity areas. You won't be facing this daily unless you shoot it daily or sit around dry firing it. Countless rimfires have survived for decade after decade after decade just fine by simply pulling the trigger on an empty chamber to uncock. Nor are they damaged by just leaving them cocked... springs don't wear out from being left cocked. I haven't had any pumpers that didn't have exposed hammers for a long time, but those I did I either did the bolter thing, simply pulled the trigger on an empty chamber or left them cocked with no problems whatsoever.