International Business Machine Corporation
-Main Manufacture and identification codes: "B"
-Main plant location: Poughkeepsie, NY.
-Average Cost to Government per completed rifle, $42.29
-Approximately 346,500 total Carbines were made by I.B.M. : About 5.7% of M1 Carbines made.
--M1 Carbines 346,500 (I.B.M., did not make the M2, M3, T3, or M1A1 Carbines)
-Serial number blocks assigned by the government
--1st block, serial number: 3,651,520 - 4,009,999 | August, 1943 - May, 1944
-Primary stock & hand guard supplier
: Rock-Ola, Jamestown Lounge, Lumb Woodworking, Sprague & Cartlton, and Milton Bradley.
-Parts made directly by I.B.M.
: Bolts, Receivers, Barrels and slides.
--Many of there other parts were manufactured by other I.B.M. plants and suppliers.
--I.B.M. was the last contractor to get into carbine manufacture. They got up to speed within a month and did a great job of getting carbines out the factory.
--I.B.M. Figured out new manufacture techniques that reduced costs and were the first to develop a new rifling procedure that greatly increased barrel production.
-All matching vs how it left the factory
****** There is a difference between an all matching carbine and how it left the factory, a lot of M1 Carbine contractors shipped parts to other Contractors. Just because its all matching doesn't necessary mean that is how it left the factory. So don't get super disappointing if your Carbine is not all matching, its possible its exactly how it was when it left the factory!!! An example say Underwood was low on sears, Inland would ship some Sears to them. Sometimes marked or unmarked. Here is some known shipments to I.B.M., how ever there could be more shipments that occurred that are unknown but this is a good reference. (most parts were shipped together in groups, magazine catches with sears, etc)
(Organized by year, 1943)
--Inland shipped approximately 10,000 bolts to I.B.M. in 1943.
--Inland shipped approximately 200 receivers to I.B.M. in 1943.
--Inland shipped approximately 27,000 slides to I.B.M. in 1943.
--NPM shipped approximately 1,000 trigger housings to I.B.M. in 1943.
--NPM shipped approximately 20,000 rear flip sights to I.B.M. in 1943.
--Underwood shipped approximately 14,000 sears to I.B.M. in 1943.
--Underwood shipped approximately 5,000 recoil plates to I.B.M. in 1943.
--Underwood shipped approximately 10,000 hammers to I.B.M. in 1943.Example
: You have an all matching I.B.M. carbine with a Inland slide, its possible it left the factory just like that.
Please feel free to PM me or post for any errors or any further information.
-Some history of I.B.M.
Here is a good site for info and history of I.B.M. http://en.wikipedia.org/wiki/Internatio ... s_Machines
-More info may be added
***General Carbine history can be found here