I like the .500" because it'll handle a .45-70 fine. (The 3/8" do seem to "dink" a little better though : )What size gongs do you all like for ranges from 400-600 yards? Also do you like 3/8 ar500 or 1/2inch thick? Thanks!
I use 4" or 6" up through 300 and an 8" - 12" up through 600. (It basically boils down to what we have at the time)
My overall favorite is a 1/2" by 6" gong.
I paint them alternating coats of blaze orange and white. That way the previous color easily shows where you just hit!