I think my issue may have something to do with the fact that I am using gunslinger mode in Hunt instead of the traditional hunter mode of aiming. I am finding a "HipMouseSensitivity" setting of 1.6 results in a hipfire 360 that is much closer to the 15.1038 inches that I expect.
I have not tested this yet, but I wonder if when using the "hunter" style of aiming in Hunt the FOV changes when you go to the first stage of aiming, which is equivalent to gunslinger mode hip fire. If this is true, then gunslinger mode may have a lower FOV than what you set in the options/config file.
Edit: I just watched some older videos of Hunt on youtube. The FOV does in fact change when you go from regular stance to gun ready. Gunslinger mode always has the gun at ready.
Using these settings give me much better hip fire results in gunslinger mode:
I am still using 59 for the "FieldOfView" setting in the config. In-game the FOV shows 90 in the options as it should.