I have at hand an old chart published by WW many years ago. Velocities are given at "Muzzle" 20 yds, 40 yards & 60 yds. The following is for shot size #7.
For MV of 1335 fps velocities are; 20yds = 930, 40yds = 715 & 60yds = 580
Loses for the 20yd increments are thus; 405fps, 215fps & 135 fps.
For MV of 1135 fps velocities are; 20yds = 830, 40yds = 655 & 60yds = 540
Loses for the 20yd increments are thus; 305fps, 175fps & 115 fps.
Total loss over the 60 yds was 755fps for the faster load, 595fps fot the slower one.
To put it another way 195 fps more velocity at the muzzle resulted in only 100 fps more at 20yds, 60fps at 40yds & 40 fps at 60 yds. Loss was for sure most rapid in the area between the 1330 & 1135 velocities.
At 40 yds the 1330 load had lost 46% of its initial velocity, the 1135 load 42% with the vast majority of this loss coming within the first 5 yds.
