I am a little late to the party on this, but I only recently found out about it. I posted my targets on the Rifleman's Challenge Facebook page.
It took me three attempts to get all the shots into the black. My first two attempts were both: eight shots in the black with two flyers just outside the black. Started raining, went home and went back out today. I was able to consistently meet the challenge when using a scope. However, was below par with iron sights. So, I need to keep practicing.
This is a nice simple drill that really shows how well YOU can shoot (not how well the rifle shoots, how well YOU can shoot). It is challenging enough that you need to have solid fundamentals to do it, but not something that requires a Camp Perry Champion to achieve. Of course the best part about it is that most people think it would be easy and are never shy about telling you so. But, I dare say that the vast majority of gun owners can't do it.
FWIW: I shot mine today using a sort of 10/22 clone. It is made up of various parts, none of which are actually Ruger, but based entirely on the Ruger 10/22. It has a Leupold Rimfire scope (2-7x). I shot it from prone with a USGI sling. I tried it several times with a 10/22 equipped with Tech Sights but was unable to keep them all in the black
I highly encourage anyone who owns a rifle to give it a try and give yourself an honest assessment of your skills.
Just remember: no bipods, no benchrest, no sandbags, no ruck sack............ prone with a sling (or not). This is a test to see how well you can shoot. The point of using artifical supports is to remove as much of the human element as possible to test the potential accuracy of the rifle. That is not what we are doing here. We are testing the potential accuracy of YOU.
