IBM Carbine

[Brasidas]

I recently purchased an IBM M1 carbine from CMP and am hoping if someone could answer a couple of noobie questions.

What would be the appropriate type of stock and would this carbine have been originally fitted with a flat or round bolt?

The carbine receiver sn# is IBM 3665XX and the barrel is marked IBM 3-43.

Thanks very much for replies. (some of you must get really tired of answering the same questions, but this beginner really appreciates your knowledge and help!) BTW, it's a nice shooter!

Information

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[imarangemaster]

I think I can safely answer this one... It should be a flat bolt. Round bolts showed up much later. The stock will have to be answered by someone more knowledgeable than I.

[dnikkor]

Not an expert, but have been helped by many. My IBM is a cousin of yours, just 16,000 later than your IBM. Yours was probably made either late September or October of '43. Unsure if your barrel could be original to your carbine, but I guess it is possible. Most likely a replacement barrel.

According to War Baby! you probably need a Type A, variation 1 stock with the "I" oiler aperture. Besides ordnance cartouche on the right side, the slingwell would be stamped RMC plus large B.

Some Type A variation 2 with oval oilers were used too marked BR-B, JL-B (what mine lives in), LW-B or SC-B in slingwell.

Definitely flat bolt with a number of "correct" or at least "possible" ones.

Hope this helps & sure an expert will correct any of my mistakes.

[ulflyer]

Brasidas: I like the IBM's as well. My 3 are a bit later than yours. What other markings do you have ...stock, trig housing, hammer, sights, slide, etc? We love to see whats coming out of CMP and to help you ident the parts.

[Bill Hollinger]

I am going to assume you left a number (X) off the end of your serial number as IBM was in the 3.5 mil range. Dnikkor could be correct because there was mixed use of stocks. However, I believe yours should a type I "I" cut stock marked RMC B as they were used into October 1943. The mixed stock use was more at the end of 1943 and into 1944. In addition, Rock-Ola gave some 50,000 stocks as well as hand guards to IBM, although later than yours. The hand guard should be LW-B or even RMC depending. SC-B, BR-B and JL-B were in use after June of 1943. I hope this helps however there are others here that are even more in the know and may chime in.


Source,
War Baby

[Brasidas]

Oops! I did leave the last x off the serial number.

The stock on the carbine is marked JL-B in the sling well and has a .U. on the pistol grip.

I'll be shooting it again this weekend and I'll post photos of the other markings after I do the cleaning.

[Neal Myers]

I wouldn't worry about what is original, or what is correct; it doesn't really matter. Your carbine has been arsenal rebuilt, so it is a mixture of new, old, & refinished parts. You really don't want to try to "restore" it. Shoot it & enjoy owning a real USGI carbine.

[BrianQ]

You need a flat blued IBM coded bolt and a highwood oval cut stock made by one of IBM's subcontractors.

The 3 in the barrel date is probably a poorly stamped 8.

Your serial number dates to September 1943.

[dnikkor]

Bill, as usual, is completely right on the stock. Since you already have a JL-B IBM "later" stock, unless you are planning on doing a complete rebuild to make your IBM "correct", you might consider doing what I have done, which is to accept it as "close enough." When I got my first carbines, I was going to restore them to their WWII configuration. After researching how hard and expensive it is to buy the correct parts, I decided that "as last issued" isn't so bad after all considering that coming from the CMP, that is how it is now configured. Incidentally, the .U. mark on the left side is a rebuild mark by Underwood. I would still love to own a WWII-configured carbine and probably the best way I will be able to do that is by buying one that is "original". Of course if you want to do it yourself, have at it and good luck.

[Brasidas]

I wouldn't worry about what is original, or what is correct; it doesn't really matter. Your carbine has been arsenal rebuilt, so it is a mixture of new, old, & refinished parts. You really don't want to try to "restore" it. Shoot it & enjoy owning a real USGI carbine.

I agree. I really don't plan on changing anything except, maybe, the stock and hand guard. It is what it is: a great example of American ingenuity and mass production. The carbine shoots well exactly as is. I'm more interesting in learning how to properly maintain and shoot historic weapons than filling my safe with things that never see the range.

My OP was an attempt to learn more about this carbine's journey into my hands.