NPM Carbine

I purchased a NPM Carbine with the S/N in the 4.25m Range. It has a T2 BB and a has a T2 Front Sight marked SN with a Trimble Stock. I was going through Riesch's Book and The M1 Carbine 3 by Harrison. In Harrison's book it has 2 or 3 pages of parts by year but does not give you the S/N range to determine if the M1 is a '43 or '44. It looks like it might be a late '43 from Harrison's description. Could someone please help me determine what year this Carbine is ? If it's a '44 then I might be able to go with a Stamped Rear Sight.:help:

Frank

USCARBINECAL30M1.com
This might help.

NPM did not produce in order, some serial numbers were completed out of sequence. I have a 4.25 with an IBM Corp barrel. These were some of the last carbines made before they stopped production in April of 1944. The IBM barrels were used at the end of production and the type 2 band would suggest a 1944 build as well. What barrel do you have and is there a punch mark on top ?

I have a Marlin Barrel. There is a Punch mark between the P and the nose of the stock and have a Punch Mark right in front of the Dovetail. I was looking at the NPM's on Newmarketarms (they have several) and they have a couple of '44 's with the S/N's a little lower than mine.

I wouldn't pay much attention to the Harrison book, it's reputation has been talked about on this site and others for years. Also, War Baby states that the SN marked front sight started being used about the end of 43 until the end of production. What kind of type two barrel band does this carbine have. The NPM band is very unique looking one.

War Baby (p. 212) indicates interchangeability testing of 6 NPM's in the 4.23M S/N range in early March 1944. All had IBM barrels (p. 446). Probably a safe assumption that these were produced in Jan or Feb of that year. NPM was cranking out 40,000 + a month in the first quarter of 1994, so would 4.25M S/N range be a little after these tests?

FWIW: My NPM, #4,272,358, appears rebuilt post WW2, but still has a Marlin barrel on it.

Frank, NPM 4.250 - 4.285 appear with Underwood 2-44 and 3-44, and undated Marlin and IBM barrels.

As DaveHH wrote -- NPMs were produced out of serial number sequence; e.g. 4.425 - 4.432 were produced with Underwood 9-43 and Marlin barrels.

This Marlin Barrel is Undated. We're all Marlin Barrels Undated. I do have the book "WarBaby", but it's being used by a friend who bought his first M1 Carbine at the last Gun Show and he is using it to read about his Carbine. He hasn't brought it back. The T2 BB has 4 weld marks and there's some greenish color to it. It also has a Sear marked SW - N. The Bolt is Flat and is Marked N 12.

All of the Marlin barrels I've seen were undated. Does the type two barrel band you have come with a small locater hole between the front weld scars? Also, they have a lower screw hole position like the Winchester type two barrel bands. If you can post a picture of it I can identify it pretty quickly. NPM carbines can be very frustrating since they went out of production sequence like mentioned. You have to look at the revision number on the side of the receiver and try and figure out when the carbine was made, then you can sort of figure out when they used a certain part, but that won't be necessarily perfect even doing it that way. Good Luck with your project.