If the gun is 37 yrs old it is NOT a light contour. Only been doing the light contour since the 1990's. The only way that it will shoot 3 inch shells correctly is if it is a magnum receiver to begin with. Now you can put a 3 in bbl on the receiver and it will shoot 3 inch shells but if it is a 2 3/4 in receiver it will not eject the empties..not very well anyway. The ejector on an 870 is fixed in the receiver and on a 2 3/4 inch receiver it is placed a little farther forward compared to a 3 in receiver. Actually the ejector itself is placed in the same spot...but the ejector is just shaped differently for the 2 3/4 and 3 in shells. If it were me I would just go buy a new 870 express shotgun with the rem chokes already in it and use it. A new 870 choke bbl will cost in the neighborhood of 200 bucks and the express guns are selling for 260 at many discount stores. Buy before the end of the month and there is a 30 buck rebate too, I think!! Check the Remington site for details on rebates. Oh ...and ya get to have a brand new toy that way.
