I can also point my Wingmaster at the ceiling and push the fore end release and the action will drop almost all the way open. On my last one it would drop all the way open. I guess Wingmasters are a lot smoother than Mossbergs, sorry - who knew.
And the standard test is either pulling back on the fore end or pushing a dowel down the barrel of an unloaded gun and pulling the trigger and seeing if the bolt stays locked.
You will also note I said I could do it firing my Wingmaster one handed, i.e. nothing restricting the fore end.