Could be a barrel sold as surplus - a majority of the durable goods sold as surplus were supposed to be “cut up” or welded to render it as scrap metal. The cut is over the Ordnance bomb which makes me think it was surplus.
Some depots did a better job scrapping than others - the CMP drill rifles were good examples of the mix of the application of the standard.
Some were cut, some were tack welded, and some looked like my high school shop project (more weld is better - right) - a number the drill rifle receivers were recovered from these.
Your barrel also could have just had brief run-in with the depot shop machinery at some point.
The 12 is probably a rack number, the letters on the left are the Arsenal or Depot that inspected, rebuilt, OR did the recertification of its condition.
I can’t pull the picture detail up - but it looks like “3GM-K” as the depot. Fort George G. Meade Depot did have some 1917, but that’s about as much as I know.
Last edited by AH64guy; 07/25/23.
