Here is some results of a comparison I did between my Ruger 10/22 with TSR200 Aperture Sights,,, and my Marlin 795 with open iron sights;
Marlin 795 (Score: 872 of 1000)
11/09/09...210-3x (Fed. #745)
11/09/09...213-1x (Fed. #745)
11/21/09...220-2x (Win. X22LR)
11/21/09...229-3x (Win. X22LR)
Ruger 10/22 (Score: 872 of 1000)
11/18/09...202-2x (Win. X22LR)
11/18/09...219-1x (Fed. #745)
11/22/09...223-5x (Eley Sport)
11/22/09...228-1x (Eley Sport)
I used the 5 Bull NRA #TQ-3/5 Target and shot 5 shots at each Bull from 25 yards using the following disciplines over a 100 shot course of fire for each rifle. The only shooting aid I allowed myself was a Sling;
Top Left Bull - Offhand, Top Right Bull - Kneeling, Center Bull - Setting, Low Left Bull - Prone, Low Right Bull - Prone...
You may want to look into the Aperture Sights;
Tech-SIGHTS Precision Shooting Accessories
A small 3-7x20 or 3-9x32 scope would have probably netted better scores from both rifles in my testing, but I really enjoyed the convenience of shooting these rifle's without a scope.
I do own and shoot scoped .22's and they have their place as well when a more finite shooting is needed. However, at my age I can't knock the results of Open Iron or the Aperture Sights.
Here is a picture of the type of target I used when I started this comparison test of sights. The Bulls measure 3-7/8" - and these two targets were shot with my Marlin 795 (Open Sights);