Quoted: where should one aim, and where should rounds impact to get a 100 yard zero shooting at a target 50 yards away. Yes i know about the Ibsz, but thats not what i want to do. I zeroing in my loopy and the BDC works on a 100 yard zero.
|
In my NRA Patrol Rifle Instructor Manual, the following info is listed on a chart using
55 grn / M193 ammo.Sight Height: 2.5 inches / Muzzle Velocity: 3250 fps / Ballistic Coefficient: .255
The following represents the point-of-impact (POI), either plus or minus in inches, from the point-of-aim (POA) using a 50 yard zero.
Range (Yards) / 50 Yard Zero (Inches)
------------------------------------------------
5 ......................... - 2.2
10 ......................... - 1.9
15 ......................... - 1.7
20 ......................... - 1.4
25 ......................... - 1.1
30 ......................... - 0.9
35 ......................... - 0.7
40 ......................... - 0.4
45 ......................... - 0.2
50 ......................... 0
55 ......................... + 0.2
60 ......................... + 0.4
65 ......................... + 0.6
70 ......................... + 0.8
75 ......................... + 0.9
80 ......................... + 1.1
85 ......................... + 1.2
90 ......................... + 1.3
95 ......................... + 1.4
100 ........................ + 1.6
What this means is that you can still zero in your sights for various distances while remaining at 50 yards. Example: You want a 100 yard zero while shooting 50 yards. On the chart, 100 yards = + 1.6 inches.
What you do is put a mark on your target 1.6 inches ABOVE the bullseye. This will be your POI. Then at 50 yards, you still aim at the center of the bullseye, and adjust your sights until your shots hit your marked POI.
* This chart applies to Iron Sights.
"Trajectories listed are provided as a
general guide. Actual trajectories will vary based on actual muzzle velocity, bullet weight, bullet coefficient,
sight offset, and other factors. Data courtesy of JBM Ballistics."