I measured an old A-23 target. This was the official 200 yard smallbore target. The 10 ring is 4.5 inches diameter and 9 inches diameter for the 9 ring. We shot this in club prone matches mainly for fun. It was not uncommon for 20 shot scores to be around 193 with a few X's . IDEAL'S post about 1 1/2" groups from benchrest is outstanding. Keeping most of your shot inside a 4inch circle from prone is an eye opener too.
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Distinguished Rifleman #731