Gravity Digital Wattmeter shunt resistor

Hello,

I'm trying to swap out out the 10mOhm shunt resistor for a more robust 300A/50mV shunt which is 0.17mOhms.

Is this even possible work out the math for this value based on a displayed reading for the default 10mOhm?

I'm trying to see if I can get a 300A/300mV shunt so it ends up being a 1mOhm resistance and then values are only a magnitude off.

Thanks,
Ryan