Thanks, Vertigo. I think you may be on to something with the shell stop button. I can't force the fore end back any farther, but the action arms still won't engage the button on the carrier latch (which is properly depressed in your picture). Is this a common problem on the Novas and, if so, have you heard of any fixes? I've come up with nothing searching on the internet
I purchased a Nova Field about a year ago. Recently, I've begun experiencing problems where shells won't feed from the magazine tube after firing a shell loaded directly into the chamber. The metal flange that holds the shells in the magazine (the carrier latch, I believe) doesn't release after firing, thereby preventing the shells from loading (pictured here: http://imgur.com/a/ywwZI). The gun has been cleaned and oiled repeatedly, to no avail. Any thoughts?