Question about unmarked barrel on Standard Products carbine

[Marcus]

I have a Standard Products carbine with no manufacturer's markings on the barrel. The finish on the barrel matches the rest of the rifle, and it has the P marking. It's definitely a military configuration barrel, not aftermarket or commercial. The carbine still has a type 2 band on it, and there are no type 3 band marks on the barrel.

Rifle looks all proper and correct for a typical arsenal refurbished/upgraded carbine.

Anybody ever seen anything like this before or have any information on it?

[Tuna]

Look on the flat of the barrel and the side of the gas cylinder for any markings.

[Marcus]

No, no other markings besides the P on top of the barrel about 4 inches back from the front sight. It looks like there is one of the little hardness test divots on the top of the barrel, right above the gas cylinder. All the little fine circular external milling marks are still visible and perfect on the barrel, so it's not like it had markings that were later worn or polished off.

There is some minor, very light and very fine surface pitting on the barrel under the wood, just behind the barrel band, the witness line on the barrel and receiver line up, and the finish on all parts is identical and consistant. Front sight is N marked and sight, barrel, and pin show no signs of having been dicked with.

Serial number is 2221325.

Overall it's a straight, very clean, honest looking, un-messed with, carbine that has been together in it's present condition and configuration for a long time.

Just no manufacturer or date markings on the barrel, other than the P proof. No import marks or any crap like that, and no indications of any foreign usage.

[Steven Martin]

Could it be Winchester? I think maybe SP got a bunch of barrels from them at one time.

[Marcus]

No W on it or Winchester proof like on my Winchester M1 carbine. Also, as I recall, the barrel on my Winchester is a lot smoother finished.

[Tuna]

Is the barrel a type A or a type B? Long skirt or short skirt? How far back from the front sight do the milling marks start? Look real close to the top of the barrel length wise behind the front sight. Is there any trace of a marking on it. It may be very faint.

[Marcus]

Long skirt. Gas block is machined as part of the barrel, not swaged on. Milling marks start 3/8 inch back from the rear of the front sight. No visible markings of any kind on the barrel other than the little P.

[Tuna]

The gas cylinder narrows it down to Winchester, Underwood, Marlin and IBM. A long skirt rules out IBM and Marlin didn't deliver barrels to Standard Products till October 1943 and also Winchester as they were used in November 1943. That leaves just Underwood and the long skirt means it is most likely a replacement barrel as the short skirt barrels were in use for many months by the time your carbine was made. As to why the maker ID and date are not on it is really anybody's guess at this point in time. Another puzzle of the M1 carbine with no answer yet.

[Marcus]

What would the approx. manufacture date of this carbine be, going by the serial number?

[jimb]

If the barrel still shows the lathe marks then it is likely Underwood.

[Tuna]

Made in 1944. Serial number 2180350 was made no later then Feb. 1944 and was used in the last interchangeability test starting March 6th 1944. Standard Products was using Underwood barrels at that time.