Spring tube markings QH

I would guess that, since QHMC made only two parts for the M1 carbine (the spring tube receiver and the spring tube itself) and used the spring tube design from the very beginning throughout their production, that spring tubes marked "Q" would most likely be "correct".

However, there's probably no one alive today who might actually KNOW. When YOUR carbine came off the line and needed a spring tube, maybe QHMC's own supply was temporarily exhausted (there was a war going on) so they scrounged some tubes from another prime contractor, which weren't marked, and used one of those. Then that unmarked spring tube would be "correct", albeit "improper", for YOUR carbine.

Actually General Fireproofing Co made the spring tubes and then National Lock Co. was added to make the spring tubes.

With either tube....nobody will ever be able to prove otherwise. People do replace components in carbines to make them correct. In the process, they very well could be removing parts that were installed on the carbine when it was born. Happens all the time.

Thanks for the help/info , if I find a nice Q marked tube I may pick one up , but like was said ... don't lose sleep over it.....it very well may be correct for this Rifle.