The result of your conversion between erg and grain/ounce [US] appears here
To convert between Erg and Grain/ounce [US] you have to do the following:
First divide 0.0000001 / ((0.45359237/16)*(192/175)/480)/(0.0037854118/128) = 0.00000005
Then multiply the amount of Erg you want to convert to Grain/ounce [US], use the chart below to guide you.
Symbol: erg
No description
Symbol: gr/oz
No description