Below 125,000 everything 'seems' to be oprod readable and long spline/pad. After that the direction of print is both directions. Shorter pads and splines 'seem' to begin transitioning in around the change in contract or right around the 1.2 million mark. As with all almost all the earlier parts at WRA, they can show up at random on later rifles. With regard to these earlier profile barrels, while they may be less common on the midwar rifles, they do show up all the way thru production and quite a few have even been seen at the very end on Win-13's.

The earliest data is terribly thin, but that is basically what the observations (of many) support to this point.