Alan...
Your probably right... there are 18 Dugger in Georgia regiments... and 5 of them are either J. M. Dugger or James Dugger... but several have conflicting service dates. Since I live in the DC area I am down at NARA or LOC about once per month and have check out all the Duggers in the civil war (on both sides).
I will follow up on your idea here!
Thanks
jim