They measure .735 which is a tad less than 18.7.
The provisional proof is at 18.4, which is a lot more standard.
I think this was done to lighten up the barrels, which are still on the heavy side.
I see no evidence of honing, so I believe this is intact from factory.
The barrel weight is a tiny bit lower than the proof mark, but my scale could lie.
WC-