Best I remember both the 20 gauge LW and the LT-20 have the K at the last letter in the serial number on the receiver.
If the receiver has a ejector inside the receiver like the 870 does then it will use a shorter tanged barrel
If it does not have an ejector inside the receiver like the 870 does then it will use the longer Tang barrel with the ejector nub or bump on it.
And I was under the impression that wot U as the last letter that indicated a magnum.
Other than a transitional mix of parts and modifications between the change of the receiver and barrel between the 20 gauge LW and the LT-20 this is the way things are. Remington was having problems with the 20 LW receivers cracking so about 1977 they changed to the LT receiver supposedly thickened in a few key places and with the sculptured ejection port amd started using the long tang barrels wit the ejector button on the tang instead of being mounted inside of the receiver like an 870 has.
