308 Barrel ID 91/CETME (Markings?)

[NorincoKid]

Hey guys, any idea what this is here?

FWIW, i tried pressing it into a CETME trunnion and lining up the pin channel and its waaaaaaaay off, like 1/4" away from where I usually see barrels set.

 

[AGG]

The only marking that I potentially recognize is in Picture 2.
Though I do not see a "1" inside, it may be the Eibar Proof House (Spain)--- final black powder proof for single barrel breech-loading rifles since 1923.

Tony

 

[NorincoKid]

I remember awhile back SARCO was selling NOS "in the white" Santa Barbara CETME barrels but I never had one in my hands to look at. This one kind of does look similar though, profile wise.

When I pressed it into a CETME trunnion it was so far off, the chamber face was probably 1/4" below (for lack of better words) the trunnion lip.

Not sure if it was maybe installed by a previous owner incorrectly, or maybe it was slapped in a HK trunnion? I know the trunnion/pin locations are slightly different between a CETME and G3 but I didn't think it was a 1/4' different.