Finding “best” zero for 223 shooting 77gr Black Hills OTM

[JCann]

This is interesting. I usually zero at 36 yards, how about y’all

 

[Kingfish]

For my intermediate range rifles like 300bo or 7.62x39 I use a maximum PBR calculator and depending on the size of the target area I input usually comes out from 35-39 yds. For my longer range rifles like 223 or 308 I use a standard 100 yd. zero and my charts to dial in my turrets. I figure my int. guns are meant more for quick shots where you can just aim center mass and know you're good out to around a couple of hundred yards. Long range shots usually give me a little more time to dial in or I can use the balistic reticle if quicker shots at distance are needed which most are set up for a 100 yd zero.

 

[JEVapa]

I zero 77gr at 100m 98% of the time. I don't zero rifles beyond that. I was trained to zero our long guns at 200m but that has turned out to be kind of bunk, especially now that we have ballistic calculators, milgrid reticles, and precision optics.
Unless you have the actual ballistics to do a 25m or 36yd zero, they don't really work very well, especially at range. Zeroing like that is for specific rifles and ammunition with known ballistics to give a battlesight zero so soldiers and Marines can hit a human out to 300m or whatever is required. Not sub-MOA target shooting.

This is what the Army does for iron sights as an example. Meters, not yards. Army and SOCOM do not use yards. Thats old news. I don't think Marines use yards anymore either.
M16A1 20" bb with M193 - 25m in the circle =250m zero
M16A2 20" bb with M855 - 25m in the circle with sight set on "Z", return to "3" = 300m zero
M4 14.5" bbl with M855 - 25m in the circle with sight set on "3" = 300m zero
M16A4 20" bbl with M855 - 25m in the circle with sight set 2 clicks above "3", return to "3" = 300m zero

SOCOM for optics
M4 14.5" bbl with M855 - 25m SOCOM BLK II target, rounds in the bullet strike circle for given optic

There are others for different weapons but these are the most common in use by the military. Everything else will be off and you won't have a battlesight zero...which is not the same as a precise zero. A battlesight zero gives a certain probability of percentages of hits on an E-type silhouette out to the range zeroed. Gunsight has a pretty good explanation.

For optics, zero at 100 and learn your holds. Irons? You're on your own, With red dots, I do battelsight zeros for those. The dot is so huge that at 300m the error is 12 inches if you have a 4MOA red blob. I use a kestrel or a ballistic app so I know where to zero for 300. Always confirm if you can.

fair warning, @KurtM doesn't like battlesight zeroes.

 

[JEVapa]

I'll add this blurb regarding the differences among these and why the zeros are so different across the board, especially with the same ammo on three of them.

M16A1 20" bb with M193 - 25m in the circle =250m zero
20" 1-12 shooting 55gr m193more velocity than 62gr but lighter projo
M16A2 20" bb with M855 - 25m in the circle with sight set on "Z", return to "3" = 300m zero
20" 1-7 shooting 62gr M855 with standard A2 FSB
M4 14.5" bbl with M855 - 25m in the circle with sight set on "3" = 300m zero
14.5" 1-7 shooting 62gr M855 with F marked FSB and shorter sight radius and reduced velocity
M16A4 20" bbl with M855 - 25m in the circle with sight set 2 clicks above "3", return to "3" = 300m zero
20" 1-7 shooting 62gr M855 with F marked FSB

 

[JCann]

I should have put the caveat that this was for red dot type sites. Not for long range applications where we all know we should either use our reticle or dial for the shot. Now, I know some red dot sights are set up for hold over. I’m not talking about those types of sights either.

 

[Kingfish]

I just remembered about a 10" sbr that I shoot 77s out of. I set at 36 yds. and it re-zeros at about 325. It has a 1.5x circle dot optic on it and I can hit what I need to at that range with it.

 

[JCann]

fair warning, @KurtM doesn't like battlesight zeroes.

He’s just eaten too many crayons, that usually makes old salts grouchy.

 

[KurtM]

@KurtM gets extremely tired of teaching LEO and DOD classes where everyone has a "great 25 meter zero" and can't even hit a 10" steel circle at 100 meters prone off sandbags. @KurtM has noticed that at least 70% of carbines sighted in in the latest 900 inch range/25 meters/ 37 yards bla bla bla technique can't even hit a C zone at 200 meters, or a 10" circle at 100. @KurtM also thinks an E type target is a rediculusly BIG target and would depict shooting at a big foot, not a average size human. @KurtM honestly thinks a nice centered hit is far better than a peripheral hit that is all a "battle sight zero" affords in the majority of cases, if even that. Keep in mind the DOD training I do is not for your average line troops, and this is what I have found. If it works for you great, but with what I have seen over lots of years, and lots of guys. I sure will be zeroing at extended range! 200 meters/yards for dots, and 300 for irons. For scopes that have a very defined aim point you can probably get away with these rediculusly close zeros because you really can define your impact compared to where the aim point really is, but I would still confirm them at range! NOW...... which color are the Bourbon flavored ones again???

You can just say Kurt.... we all know who that is