[innocent_bystander]

Here are the trajectories with different zeros using Federal reduced recoil slugs out of an 18" barrel with ghost ring sights.

Yards Trajectory

0 -1.0
25 +.9
50 +1.3
75 0.0
100 -3.2
125 -8.6
150 -16.2

0 -1.0
25 +.3
50 0.0
75 -2.0
100 -5.9
125 -11.8
150 -20.1

 

[innocent_bystander]

If you have access to a ballistic program then you can use the following:

Federal slugs weigh 438 grains and their ballistic coefficient is .109.

 

[innocent_bystander]

How much does a grain weigh?

1 pound = 7,000 grains