Just purchased a 870 express youth walnut. Looking to drill and tap the receiver for a 2-7 Leupold. I don't want to use a weaver 429m base if I don't have to. Does anyone know which Leupold 1 piece or 2 piece bases fit on the receiver? Do the 7400, 7600, 750 etc. bases fit? Just personally like the looks of the Leupold bases and rings. Thanks in adavance!!