For the guys shooting open sights, at 5m you want the black to be approximately 30mm diameter. This is roughly 50% of the diameter of the 10m NRA/ISSF target.
What JQR has is about right, although the rings could be a little bit bigger. FYI, here are the ring diameters for the NRA/ISSF 10m AP target and a 50% reduction for 5m
10 ring, @10m = 11.5mm, @5m = 6mm
9 ring, 27.5mm, 14mm
8 ring, 43.5mm, 22mm
7 ring, 59.5mm, 30mm, outer-most black ring
6 ring, 75.5mm, 38mm, inner-most white ring
5 ring, 91.5mm, 46mm
4 ring, 107.5mm, 54mm
3 ring, 123.5mm, 62mm
2 ring, 139.5mm, 70mm
1 ring, 155.5mm, 78mm
When I made my 2 and 6 bull 10m AP target, because of the overlapping targets, I dropped the outer rings keeping on one target only rings 10-5 and on another rings 10-6. And for the 6 bull target, I cut the 6 targets apart and shot them individually, to reduce distraction and to be similar to the regulation 10m AP target which is 1 target per target sheet.
The bull on the AR5 target is close to 50% of the 10m AP target, but the rings are so much smaller. I don't think you guys will like that target, because your scores will be much lower, because of the smaller rings.
JQR
I know what you mean, I have a several hundred 10m AP targets. Got them when I was more active shooting 10m AP. Should keep me going for a few years :-)
How do you like the Pellant target program? The only thing it won't do is print an X-ring for some of the NRA targets.
TC
I have a Umarex/Walther CP-99, my fun AP. I painted the back of the front sight orange for exactly for the reason you said, the front sight almost disappears against anything dark. Going to do that to my PPK also, but w the PPK shooting BBs I have to be careful where I shoot, to minimize ricochets. :-(