New GI barrels were always "short chambered" so that the head space could be set correctly to the bolt using a finish reamer. I just finished up two 03-A3 builds using NOS barrels and drill rifle receivers. Both had to be finish reamed.

---------- Post added at 07:18 PM ---------- Previous post was at 07:14 PM ----------

How did you get the plugs out? All the ones that I got from the CMPicon auction had the plug welded to the barrel which ruined the barrel.