Inland M1 Carbine Serial Numbers Dates

Owing to the scarcity of original M1A1 carbines, here are a few essential things for collectors to look out for. It should be noted that original un-rebuilt M1A1s are very rare and the vast majority of M1A1s on the market, have either reproduction or fake stocks. Also, since the war, many will have been rebuilt with later parts.

As far as I can tell highest known IBM receiver serial number is 3968546 so either 39342XX or 3909342 would be within the range of known serial numbers (they started at 3651520). Very interesting. Probably need to find a real avid M1 carbine collector to get to the bottom of this.

M1A1 Serial Numbers

Inland Manufacturing Division of General Motors was the only manufacturer of the M1A1 and manufactured approximately 140,000 by the close of the war. The M1A1 was manufactured in two main production runs, both of approximately 70,000. The first was produced and delivered from late 1942 through until October 1943. M1A1s produced during this run will have early production features, such as flip sights, type 1 barrel bands, high wood etc.

The second production run, started in April 1944 and finished at the end of 1944. M1A1s produced during the beginning of the second run, will have the same characteristics as the first run, but towards the end of the run, will have features typical of a late M1, such as low wood, adjustable sights and even type 3 barrel bands at the very end of the run.

There are no actual records kept for M1A1 serial numbers and so unfortunately there is no specific way to identify if an M1A1 is original from the serial number alone. Also, during an Arsenal re-fit, M1s produced by other manufacturers could be fitted to M1A1s.

In personally examining real examples both in hand and from pictures, I have noted some of the serial numbers and barrel dates used.

First Run
Dec 1942	123xxx
Dec 1942	142xxx
March 1943	220xxx
March 1943	260xxx
March /43	317xxx
June/43	454xxx
July 43	529xxx
Sept 43	852xxx
Oct 43	866xxx
Second Run
3/44	5,102xxx
3/44	5,163xxx
3/44	5,279xxx
5/44	5,231xxx

There are many details, but here are the main things to look at:-

Manufacturer

All originals are manufactured only by the Inland Division of General Motors.

M1A1 Stock

M1 Garand and Carbine Club, M1 Collectors Club, BIRTH OF THE M1 CARBINE. Studler, Chief of the Small Arms Development Branch of the Office, Chief of Ordinance was one of the driving forces behind the carbine.
On all of mine the serial number is under the manufacturer's name. (Rockola, Inland, Underwood, NPM, IBM) nor have I found any reference to an Underwood marked with the serial number over a U. Early Universal M1 carbines were assembled from surplus USGI parts except for the receiver which they produced; thus, possibly, the serial number over a U.
He goes on to say that 3,542 completed carbines were at the factory when taken over by Saginaw, Grand Rapids on Jan. 11, 1944 (observed serial numbers for these carbines are below 1,750,000). All other carbines, approximately 50,000 in number, were produced by Saginaw with IP receivers.

All original M1A1s are made of walnut. Any other wood is wrong. Also, check out the shape and angles around the cut away for the folding stock. Fake or reproduction stocks often get this wrong.

The Pistol Grip

The side or back of pistol grip, should have a “P” proof mark, either circled or un-circled, indicating that the gun has been test proof fired.

The underside of the pistol grip should have a marking of OI and a crossed cannons emblem.

The Stock – barrel channel

There should be an OI stamped on the inside of the barrel channel. The OI stands for Overton Inland, who were the manufacturer of the stocks.

The Butt Stock

In the butt-plate number B257614* should be cast with a logo of a sunburst in a circle completed by a drawing number between 3 and 12.