it depends on how much fat you have on your legs. I am not a large man now am I a skinny man and I still use 5.5 to 5.75 on the legs. I extend my legs out so the skin is not tight. But I too only shoot the top half of the thigh, anythign below that bled a lot and I could not get the adjustment right.
In the Copax shot diary book, this is what it says:
- if you can pinch about 1 inch of fatty tissue, try a 6 setting
- if you can pinch about 2 inches of fatty tissue, try an 8 setting
- in lean or muscular areas where ther is very little fatty tissue, try a 4-5 setting
off, like tonight i did not go deep enough on my arm and it is stinging like hell....