Older 870 (guy who claimed to know from serial number says 1972-1973) unslotted carrier, receiver is for 2 3/4" shells only. The barrel on it is off of an express magnum and is marked 3" but I think they might cause problems with the receiver. Gun is marked U.S. under the ejection port.
I do not know the history of this gun so I don't know why. The original barrel is included and has what looks like the heat shield/bayo mount intended for the Winchester trench gun modified to fit. I changed it because the bayo mount interfered with the mag extension and tac light. Speed feed 4 shot stock, 6rd side saddle and an anodized red aluminum shell follower. $450 FTF IN DAYTON OHIO AREA ONLY. EMAIL AT.......................email@example.com