Sorry, I said bore twice. I initially measured 4 1/2 inches past the chamber (because it was easier with my gauges)and got the larger numbers . Mesuring from the bore end (and pushing the gauge through the chamber) resulted in the smaller numbers.
I'm using an old style telescoping gauge which can lock. I then measure it with calipers. There is plenty of room for error, but it is what I had on hand.
I think pits were honed out of the barrels and the area just past the chambers was the most pitted and therfore got honed out the most.
I will have it measured with a bore gauge and a wall thickness gauge before thinking about firing even low pressure loads.
