Picked up a second hand Mossberg 12 ga. at a very reasonable price. Gun is beautiful, in fact as far as anyone can tell it's never been fired. Took it out last weekend and it won't eject shells. A couple of internet searches and what I come up with is (a) tearing apart to examine for cracked ejector or (b) first just trying a different brand of shell, as the gun just may need some "breaking in". Anyone run into this with the Mossbergs? My experience has always been one of great reliability. Thanks for any help.