Winchester Model 1; action problem

[247Nino]

posting this problem for a friend...

1956 Winchester Model 1 Semi-Auto 12ga shotgun

The action on this gun closes on an empty tube and chamber.
He hasn't taken it apart or brought it to a gunsmith but has expressed that he would like to shoot trap one last time before he retires it and puts it in safe keeping. All parts are original and he wants to keep it that way.

I've done some previous searches and haven't found anything useful yet...

please help
advice and gunsmith recommendations are welcomed.

thank you
-Nino

[prc77]

post it over at www.shotgunworld.com better help on these type of ??