This is the 1907 Hunter Arms Chamber Specification
Forcing cones are slightly less than 1/2". The cone angle was shallower in the 1935 drawings with a length of about 5/8".
The forcing cone appears to be cut straight, BUT this is a Cerrosafe chamber and forcing cone casting, and there might be a slight Ogee
I have an Ithaca Specification drawing from 1935 kindly provided by Walt Snyder, which also shows a straight forcing cone angle