There is much more to shooting spots than there is to shooting groups in your back yard,MUCH MORE.
Spots is a stamina and consistancy game,mostly mental once you get past consistant form and shot sequence.
1 more thing about a group,it is NOTwhat size diameter the arrow fits inside of,it is what size diameter the arrows will touch.[8D]
I do agree that our average groups are no where nearas good asour best groups.
I put 11 arrows in the blue ring(2") on a morrel outdoor range target one time at 30 yardsand the 12th was just out.That was when I was shooting a couple hours EVERYDAY and those were fat shafts(nitro stingers).I did it just to see if I could put the whole dozen new arrows in the spot,I couldn't.
Now,I am lucky to shoot a 2" group consistantly at 20 yards.