3 Steps for a 5.9" compressed 0 - 300 SOB zero
1. Determine each of your Rifle's SOB (Sight over Bore). Sharpie it on the rifle.
Measure from the center of the sight to the center of the barrel (bore). This will be the "Start" position that you see on the SOB Zero target.
2. Look at the SOB Chart below to determine your Zero Distance (yards) based on your measured SOB in inches.
Each of the zero distances in the chart have been optimized to "compress" the 0-300 yardage to the sweet-spot of 5.8" to 5.9" for your particular rifle.
3. Download the target below that correlates to your SOB measurement. Targets are adjusted for 20 yard indoor range or full-length outdoor range.
3. Download the target below that correlates to your SOB measurement. Targets are adjusted for 20 yard indoor range or full-length outdoor range.
The targets below correspond to the SOB heights from 2.5 to 4.5 inches. I've also added to the left side of each target the precise trajectory for your rifle. Additionally, the longer yardages from 350 - 500 are included in the bottom left corner. This one sheet contains your zero, and your holds for your rifle. Easy to commit to memory and you can "see" everything.
SOB Zero Distances
Notice how each Zero Yardage changes at each SOB to produce a 5.9" 0-300 yard compression.
EXPS_3 on a Unity Riser on my BCM (3.5"SOB)
** Notice how the 5.8" to 5.9" compressed "sweet-spot" is precisely at the 61 Yard Zero **
Swampfox Blade on my Hellion (4.5"SOB)
** Notice how the 5.8" to 5.9" compressed "sweet-spot" is precisely at 85.25 Yard Zero because the SOB is 1 inch taller **
free SOB targets
I've created a set of SOB targets below that you can choose from and download based on the sight over bore measurement for your particular rifles. Included on the left side of each target is the actual 556 trajectory customized for your rifle. And in the lower left corner I've also added the longer distances out to 500 yards based on each zero. You can shoot each target at the indicated yardage to zero your rifle, or if you only have access to an indoor range I have optimized them for 20 yards also. After zeroing your rifle, you will have a 0-300 yard spread of only 5.9", and you will have your entire ballistic spread on 1 piece of paper. WD3D
One Final Recommendation - Get A Range Finder to Practice
Study your SOB Target and Holds
I would highly recommend getting a small range finder and randomly looking at distances while you have your SOB target beside you. Begin to notice, and practice determining, how far away things are and how they relate to the dots on the left side of your SOB target.
Become very familiar with your SOB target and your holds. Commit them to memory. And then practice using your range finder to get better at determining various distances.
Perform this easy practice regularly:
Look with eyes - Guess distance - Measure with finder
Look at SOB target. Repeat
Your ability to effectively determine the distance to an object with only your eyes while at the same time knowing your rifle's zero and trajectory are crucial to your abilities.
If you have any questions please contact me through the website, and if you are radio licensed, my email address is correct on http://www.QRZ.com
I can even generate a custom target for you if your SOB is not listed here.
73, WD3D | Eddie James