Hi Amir.
The targets are different sizes for different types of shooting. The black aiming marks should appear the same size to the shooter whatever the range.
The target sizes as listed in the NRA 138th Imperial meeting book
Target Rifle
Ranges in yards Sizes in inches
Division - Long Range- 600 - 500 - 400 - 300 - 200 - score
Aiming Mark - 48 - 39 - 39 - 32 - 22 - 16
V Bull - 14.4 - 7.8 - 6.3 - 4.8 - 3.3 - 2.1 - V
Bull - 24 - 13 - 10.5 - 8 - 5.5 - 3.5 - 5
Inner - 48 - 26 - 26 - 16 - 11 - 7 - 4
Magpie - 72 - 39 - 39 - 24 - 16.5 - 10.5 - 3
Outer - 96 - 52 - 52 - 32 - 22 - 16 - 2
Hit 118 w [70 wide x 60 high] [ 46 inch square ] - 1
F Class
Aiming Mark - 44 - 39 - 39 - 32 - 22 - 16
V Bull - 5 - 4.5 - 3.75 - 3 - 2.25 - 1.5 - 6
Bull - 10 - 7.8 - 6.3 - 4.8 - 3.3 - 2.1 - 5
Inner - 20 - 13 - 10.5 - 8 - 5.5 - 3.5 - 4
Magpie - 30 - 26 - 26 - 16 - 11 - 7 - 3
Outer - 44 - 39 - 39 - 24 - 16.5 - 10.5 - 2
Hit - 60 - 52- 52 - 32 - 22 - 16 - 1
Hope this helps. I tried to do it as a table but couldnt figure out how too