40 yards
When shooting in the longer yardage classes,you HAVE TO judge yardage,regardless of what speed you shoot if you want to win.
I didn't actually start winning untill after I quit going to the national ASA shoots but I started winning in ASA equivalent courses against some of the same guys I was losing to nationaly.
(I did win plenty in the pro ams and I usually shot better in them,actually pretty darn good at times)