That is a G-55(or G-60) Royal,they cost as much to build as a best London sidelock.There may be nothing wrong with the action.Greener Self-Acting Ejectors eject before they cock,if you don't open the barrels far enough the gun will not close!
My 10 bore Greener G gun still kills geese every spring in SD,it's a great gun,but a bit misunderstood.