From what I observe, I believe, that the Johnson Automatic replacement barrels during WW2, were manufactured by Remington. The Characteristics of 03A3 Remingtons are wide lands, very narrow groove, along with the same front sight... having one vertical and two horizontal key ways, like the the JA barrels. The original 17 barrels only having one vertical key way.
I know my opinion is unsubstantiated, and was wondering if someone can tell me what the real deal is. In C.S. Ferris' book "U.S. Rifle Model of 1917" He mentions RIA using Remington blanks.
Any help Is appreciated....Ralph