The result of your conversion between inch ounce and grain/ounce [US] appears here
To convert between Inch Ounce and Grain/ounce [US] you have to do the following:
First divide 0.0070615518 / ((0.45359237/16)*(192/175)/480)/(0.0037854118/128) = 0.00322282
Then multiply the amount of Inch Ounce you want to convert to Grain/ounce [US], use the chart below to guide you.
Symbol: in oc
No description
Symbol: gr/oz
No description