I know this should be simple but I am confused. I picked up a used 870, which I thought to be a 870 Express Super Mag Synthetic in 12ga. Both barrels that it came with are marked as 12 ga and both barrels fit the receiver without issue. I am able to feed 12 ga dummy rounds though it with no problem. The problem arose when I was checking the serial number on Remington's website to make sure it would take 3 1/2" shells. Per Remington's website the Super Mags serial number end in "A" and other 12 ga should end in "V" or "M". Mine ends with a "U" which designates it as a 20 ga. Would 12 ga barrels and 12 ga shells work with a 20 ga receiver ? I have emailed Remington but don't expect a response for some time.
Thanks.
Thanks.