On targets:
the 200 yard and 100 yard assra targets are proportional to distance and are faithful reproductions of the Historic Schuetzen targets - with the exception that the historic targets went out to the 1 ring,  and the black was always out to the 18 ring.  (of the many targets used in various contests of schuetzen - especially the CSSU- the 12 inch black was always present except for the Mann target.  This for aiming with iron sights.)

The target that the Davenport Shooting Association uses indoors at 50 feet is a reduction proportional to the distance from the 200 yard target.  As near as i can tell this was introduced about 1930.  This was a local phenomenon and that target is not used anywhere else that I have found in my limited scope of research. A .22 bullet makes a hole that is 2 rings in diameter on this target so scoring to the leaded edge can add a point to each shot.  The nearby Wheatland, IA club used a similar reduction indoors at 75 feet also in the 30's.

The target used in gallery shooting in 1898 to 1920 (in Davenport and nearly everywhere else) at 75 feet had 1/4 inch rings.  This is much larger than the target used in Wheatland that was proportional to distance.  The ASSRA target appears to me to be a reduction of this target from 75 feet to 50 feet.

I have some question as to whether the 1/4 inch ring gallery target was actually 0.24 inches per ring or 0.25 inches per ring, but 1/4 inch seems close enough either way.