Just to add my two cents. I have examined examples of Philly era Fox guns that have H size frames with standard .729 bores. These guns are not called H's on the factory cards, they are referred to as something like "make as heavy as possible" and weight 8lbs plus. All of the HE's I have measured have overbore barrels and are always referred to as H's on the factory card even if they are graded eg CHE, XHE. The gun in question falls outside what I have observed. But ya never know.