while browsing for some target shooting results, I've come on this page: http://www.chuckhawks.com/alternative_practice.htm

and I don't quite get it here(or do i?):
"The rifle target is ten rows of six 3/16" black dots on an 8.5x11" sheet of copy paper"
does he speak about concentric circles, first 6 black and the other 4 as it is (white)? or another formation
http://www.shutterstock.com/pic-28654969/stoc...oting.html

if this is the case (concentric circles) then 3/16" means the diameter of exterior black circle will be 3/16x6 (4.76 mm x 6 -the number of black dots) or 3/16 is the radius