The result of your conversion between Iron and grain/ounce [UK] appears here
To convert between Iron and Grain/ounce [UK] you have to do the following:
First divide 7658 / ((0.45359237/16)*(192/175)/480)/(0.00454609/160) = 3357.88414689
Then multiply the amount of Iron you want to convert to Grain/ounce [UK], use the chart below to guide you.
Symbol: iron
No description
Symbol: gr/oz
No description