I zero off a sandbag at 25 yards. I use a silver ink Sharpie to mark that spot on the turret.
A 25 yard zero is also a zero for about 275 yards. That is, if you want to change the zero to 100 yards, you have to come DOWN about 4 minutes.
But, for a dedicated CQB rifle, a 25 yard zero is about right.
Remember the scope is about 2.5" above the bore. So at 25 yards the bullet has been aimed UP to intersect the line of sight, 2.5 inches above the bore.
At distances beyond 25 yards (I think we shoot at 30 and 35 yards) the bullet will keep rising, and hit high. So I aim at the bottom of the white, or a bit lower.
As we advance on the target, closer than 25 yards, we have to aim higher and higher. I aim at the center of the white, until I get to 15 and 10 yards. Then I aim at the top of the white.
For Modified Prone, use the practice session to get a solid idea of where you have to aim. We get to shoot 10 shots in Snap (2 shots per whistle. Instead of shooting the 2 shots on 2 targets, shoot them all on one target. For the Rapid, shoot all 10 at the other target.
This will give you a pair of groups to look at to assess where you have to aim to put them all in the bull.
Do you have an idea now of where the gun shoots in MF? If so, use that info to pick an aiming point. If you don't know, aim at the top left corner of the white wrist mark.
If you have a zoom optic, crank it up a bit. I shoot MF on 5X. As the group forms, I can see it. I look at the Snap group, make a guess for a better aim point, and then shoot the Rapid at the new point. From that result I can make another adjustment of where to aim, if needed.
This is my 10 SNAP shots aimed at one target. I aimed at the center top of the white. It looks like I should aim a half inch lower, to make sure I get 10 bulls. The two out to the left are from the standing Rapid.
