I run 300/450/ and 600 coppers all with the same lead (or close to it). Like you stated I eyeball it, but I have somewhere between 35-50’. I had a lead get short maybe 20’ or so and it went “dead” after i lengthened it, it started producing again. Maybe the day ? Couldn’t tell you but if it ain’t broke ........ Sent from my iPhone using Lake Ontario United