Difficult to ID spare M1 Carbine barrel?

Hi!,
I have a goodly number of NOS, in-the-wrapping, USGI M1 Cabine barrels that I am unwrapping and going through the markings and stampings.

This one is a little difficult to precisely ID, with the minimal stampings.

- NO front/top of barrel markings
- large letter 'B' (only; not 'BI') on the underside of chamber flat area
- Ordnance cannon wheel stamping, rear of underside chamber flat area
- capital letter 'M' on the side/top of the barrel chamber
- T4 front band has stamped capital letter 'Q'
- witness line mark on bottom of the chamber
- 'WI' marked gas piston
- NO other markings on swaged gas cylinder body/front/sides
- tube is 4-lands/grooves
- flat muzzle

.....my guess from the markings/stampings visible is an GM-Inland Div.(prime contractor) spare barrel made by GM-Brown-Lipe-Chapin Div. as the subcontracted actual manufacturer, though the 'B'(only) stamping is troublesome......I looked VERY closely, and while it may be possible that the expected missing 'I' is just super faint and readily discernable, it doesn't appear so??

Anyway, have a look through the attached pictures, and I'd greatly appreciate any thought sor comments!

- TomHAttachment 136705Attachment 136706Attachment 136707Attachment 136708Attachment 136709Attachment 136710Attachment 136711Attachment 136712Attachment 136713

I'm no expert but the ordinance wheel on the flat is a characteristic of a Springfield armory barrel. Other makers probably had them on the flat as well but where it's absent most usual markings, that would also indicate Springfield armory in my opinion. Hopefully the experts will chime in

According to the CCC website, Springfield armory barrels can have the ordinance wheel on the barrel flat and no other markings on top of the barrel near the front sight which seems to match your example. I'm not sure about the capital M or the B, that everything else seems to say Springfield armory

Buffalo Arms also used a crossed cannon stamp on the barrel flat along with a letter. BA barrels are also known to have a marking on top of the barrel near the chamber area.