Question on late Inland Carbine,

[smoky]

I have been collecting carbines, 1911s and Garands and others for a long time. I know many on this site have more intel. than I. So , here is my question.
I just picked up a Inland M1 at the Lewiston Gun show. Ser # 6431xxx with nice stock. typ 2 band, even finish on parts. All parts are Inland and correct EXCEPT, It hase a Underwood barrel.
From what I can tell it has NOT been through a rebuild. The ser# of the Inland looks like AUG. 1944. The date on the Underwood barrel looks like 8-1944 with the cross canon and P witch is very hard to see. Hardly no tale on the P and looks like a Underwood P.
Has anyone come across this before ? The carbine really looks like it was built that way I would not have thought Inland would use a Unerwood barrel. But I did see that the Underwood contract was over in 1944 so, May be they were dumping parts.
I know someone here would have info. on this goofy Carbine
Thanks very much for any help and have a great Thanksgiving.
smoky

[Tuna]

It is a replacement barrel. As you know Inland made their own barrels. A 6.4 serial number dates to about October/early November 1944. Now Underwood ended production at the end of April 1944. Any spare parts were gobbled up by Winchester. Barrels were made by Underwood under a separate contract to make replacement barrels for damaged or shot out barrels. September 1944 I think is the last date I have seen on an Underwood replacement barrel. Inland gas cylinders were know to crack sometimes. The fastest and easiest way to fix that was to change the barrel.Replacement cylinders were not available at that time and welding the crack did not work so replacement was standard back then.