Re: Shunt's revisited
Sceadwian,
See the wire tables in the CRC Handbook of Chemistry and Physics (Available at any decent library) for resistance per unit length for various wire sizes. One of the problems with copper wire is that its resistivity changes considerably with temperature. Since you are only using an 8 bit A/D converter, I'm assuming that you're accuracy requirements are not stringent, and therefore this is not a prbolem for you. Another option is to use one of the commercially available shunts (available from Vishay and others) and change the gain of your amplifier to get the propler scaling for maximum resolution from your A/D converter.
Regards,
Kral