Zen of the 100 Yard Zero

[Evil Bert]

I use the same method when i zero by using this target. It is setup to be placed at 25m and if done properly, it will yield you a true 100m zero and all the benefits that come with it.

[Failure2Stop]

I use the same method when i zero by using this target. It is setup to be placed at 25m and if done properly, it will yield you a true 100m zero and all the benefits that come with it.

I only accept a 25 meter zero (1.5" low) if a 100 meter range is not accessible. I have never seen a 25 yard/meter expedient zero require no change at 100 yards or greater.
If 25 is all you got, do what you can, but don't think that it's the same.

I also have no use for dedicated short range zeroing targets. I just move POI to 1.5 inches low on whatever I can aim at easily and move back to 100 for the real zeroing as quickly as possible.

[swedeboy]

Thanks for the info

[doubletap2211]

F2S, just wanted to say thanks for this post. Excellent resource for a great zero.

[Steve]

Very well done sir

[Kodiak]

Question: You stated to shoot 1.5" low at 25 yards. From the center of my red dot to the center of my bore I measured 2.75". Should I be shooting 2.75" low at 25 yards or still shoot 1.5" low?

Thanks and great read!

[SMETNA]

Question: You stated to shoot 1.5" low at 25 yards. From the center of my red dot to the center of my bore I measured 2.75". Should I be shooting 2.75" low at 25 yards or still shoot 1.5" low?

Thanks and great read!

Your POI should be 1.5" lower than your POA at that distance, regardless of your optics' height over bore.



What I think he was saying is that in general, shots landing within a 3" circle is pretty reasonable for combat accuracy. So if you zero at 100m, and if you aim 1.5" high at anywhere between 25m and 200m, your shots will always hit inside that 3" circle. This does not take into account the inaccuracy of the ammo or the weapon. If everything else is gtg, 25m - 200m should involve zero guesswork using this method.

[BangBang77]

This may sound like a dumb question, but for the 100 meter/yard zero, what do I set my rear elevation knob at during the zero process?

The only zero process I am familiar with is the 25 meter zero that I learned at Ft. Benning back in the 90s, where you set the knob at the Z marked position for the M4.

I have a LE6920 flattop, using a LMT rear sight instead of the carry handle and Troy Alpha freefloat. 16" bbl, standard front site base.

I've read this entire thread multiple times along with Molon's thread on zeros and trajectories and I haven't found a definitive answer. Both of these threads have a plethora of outstanding information. Thanks for all the hard work each of you have put in.

[Failure2Stop]

This may sound like a dumb question, but for the 100 meter/yard zero, what do I set my rear elevation knob at during the zero process?

The only zero process I am familiar with is the 25 meter zero that I learned at Ft. Benning back in the 90s, where you set the knob at the Z marked position for the M4.

I have a LE6920 flattop, using a LMT rear sight instead of the carry handle and Troy Alpha freefloat. 16" bbl, standard front site base.

I've read this entire thread multiple times along with Molon's thread on zeros and trajectories and I haven't found a definitive answer. Both of these threads have a plethora of outstanding information. Thanks for all the hard work each of you have put in.

I personally prefer to use a variation of the 100 meter zero that is similar to a 50 or 200 meter zero, and for that setup (2 inches high at 100 meters) the rear sight is set to 6/3 -4 (will require resetting the rear elevation drum as per the IBZ if you want to retain the ability to dial for distance).
You can simply spin the elevation drum to 3 (6/3 no gap) if it has not been set to allow negative travel below 3. That's essentially all you are doing when you reset the rear drum anyway, except that you can set it correctly to account for trajectory at long range.

[BangBang77]

I personally prefer to use a variation of the 100 meter zero that is similar to a 50 or 200 meter zero, and for that setup (2 inches high at 100 meters) the rear sight is set to 6/3 -4 (will require resetting the rear elevation drum as per the IBZ if you want to retain the ability to dial for distance).
You can simply spin the elevation drum to 3 (6/3 no gap) if it has not been set to allow negative travel below 3. That's essentially all you are doing when you reset the rear drum anyway, except that you can set it correctly to account for trajectory at long range.

Roger that, F2S. Much appreciated.

My department rifles are zeroed with the 25/300 meter zero. My sheriff and most of my fellow deputies are former .mil so we are all more familiar with it. We've actually been discussing going with a different zero and I think this is the answer we've been looking for.

We're a small rural department of only 8 full time deputies with limited fund so do you mind if I use your charts for reference only (no printing) to get my boys squared away?