What Is Your Zero?

[bhayles]

M&P 15 Sport...

I see folks on different threads here mentioning how they have their AR's zeroed, but they are all over the place...25, 50, 100 yards.

Where do you zero yours, and why?

 

[ChattanoogaPhil]

Sometimes I zero at 50yds... and sometimes 200yds... I also find it useful to be about an inch high at 100yds... I just can't make up my mind

 

[JaPes]

50 gets me to 100 then it's holdover from there

 

[Chew]

I have mine at 1-2" high at 100 yards (my M70 Winchester in 30-06 deer rifle is the same). The places I hunt are all 0-250 yard shots. For coyotes, I just put the crosshairs on them and let it rip and don't worry about holdover with this zero.


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[Rastoff]

50 gets me to 100 then it's holdover from there

No, not really. Phil was closer. Holdover won't be used until past about 220 yards.

Because of the trajectory of any bullet, there are two points of coincidence with the point of aim(POA). This is because the sights are above the bore.

If the .223Rem round is sighted in at 100 yards, the bullet will be closer to the apex of its trajectory at point of impact(POI). By hitting at the apex, there will only be one point where POI=POA. Thus, sighting in at 100 yards makes shots longer than 100 yards more difficult because it will require more hold over.

Sighting in at 50 yards means that POI will equal POA at 50 yards and at about 220-225 yards. Using this zero point means that at 100 yards it will hit about 1" high. By using this zero, the rifle becomes much easier to use out to 300 yards. This is so because the bullet drop at ~220 will be 0" and at 300 it will be about 6". It drops off dramatically after that.


All of this is somewhat notional. Trajectory depends on many variables. Speed, ballistic coefficient, spin, etc., are all players in how the bullet flies.

 

[CrustyShellback]

I've read topic, after topic on this. So much, the topic is starting to make me nauseous. Last night while dozing off, I stumbled onto I think the best short and to the point video, on zeroing.

AR-15 - The BEST Way to Zero

Of course, everyone has opinions...

 

[Rastoff]

I stumbled onto I think the best short and to the point video, on zeroing.

Man, I wish I had said that!

Couple of issues with that video. When he showed himself shooting to zero in at 100 yards, he wasn't using a rest. This is a mistake and can drive you crazy. When zeroing any gun, it must be shot off a rest. This removes the human element as much as possible.

Then, while those "zeroing targets" he had are good, you have to be sure it matches your optic adjustments. It looks like he has an Aimpoint PRO. That has 1/2 MOA movement per click. What if your optic is graduated in mrads? What if it's 1/4 MOA? Just be sure you have a target that is matched to the adjustments in the optic or you'll be scratching your head more.

 

[Rastoff]

Here's a better view of the trajectory targets:

It is an excellent picture of why a 50 yard zero is good for the .223Rem round. It isn't the last word though. Remember, that trajectory depends on the bullet speed, ballistic coefficient and optic height over bore.

 

[Ricer2231]

Zeroed at 100 because that's what my scope calls for.


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[CrustyShellback]

Man, I wish I had said that!

Couple of issues with that video. When he showed himself shooting to zero in at 100 yards, he wasn't using a rest. This is a mistake and can drive you crazy. When zeroing any gun, it must be shot off a rest. This removes the human element as much as possible.

Then, while those "zeroing targets" he had are good, you have to be sure it matches your optic adjustments. It looks like he has an Aimpoint PRO. That has 1/2 MOA movement per click. What if your optic is graduated in mrads? What if it's 1/4 MOA? Just be sure you have a target that is matched to the adjustments in the optic or you'll be scratching your head more.

There's always going to be variables, with different setups.

My main issue with all the zeroing madness is guys making it so difficult and this long drawn out process, for something I've never experienced so much debate about, in my lifetime.

Yeesh, we used to get our rifles, slap a scope on there, or just sights and out to 100 yds. Now, there's opinions from every branch of service, 3-gun guys, hunters, target shooters, etc...

I just want it to hit what I'm aiming at, without turning it into brain-burning, projectile mathematics. I was tired of that, after I did the data dump from 'A' School.

 

[gunny4053]

I tend to follow the old methods I learned and used in the military. Why, because it works for me. Zero at 25 meters (39.4 inches per), dead on at 250 meters. Aiming at the head at 300 meters, gives me a COM hit. Since I don't shoot for clover leafs, minute of bad guy is more than adequate, especially for an old blind guy.

 

[ChattanoogaPhil]

Oooops... Forgot the why.

Battle rifle with 1x red dot-- For all practical purposes a 50yd zero is a 200yd zero with less that a 2 inch variance. What this does is make my rifle a center mass fast target acquisition point and click device for distances that I can reasonably shoot offhand.

I got a 1x red dot to keep things fast and simple. I use a 50 yard zero to compliment that.

 

[Rastoff]

I just want it to hit what I'm aiming at, without turning it into brain-burning, projectile mathematics.

Isn't that what we all want? Unfortunately, bullets don't fly straight. If you "just want to hit what you're aiming at" and that includes different distances, the math must be done. It doesn't matter what scope or bullet or rifle, they all fly in an arc.

 

[Rastoff]

Zeroed at 100 because that's what my scope calls for.

What scope do you have that dictates where it's zeroed?

 

[Maddmax]

I tend to follow the old methods I learned and used in the military. Why, because it works for me. Zero at 25 meters (39.4 inches per), dead on at 250 meters. Aiming at the head at 300 meters, gives me a COM hit. Since I don't shoot for clover leafs, minute of bad guy is more than adequate, especially for an old blind guy.

Old methods learned here too. Can't remember the target name for sure Estonbull ??? 1" high off the X at 25 yards and I still hit things just fine at 300 yards. .

 

[Culina]

a 200 yard zero seems to work for me on battle rifles, it means I won't be missing anything up close and it gets me out to 300 yards without worrying about holdover.

 

[Rastoff]

200 yard zero that gets you 300 yards with no hold-over? Magic bullet?

 

[CrustyShellback]

Isn't that what we all want? Unfortunately, bullets don't fly straight. If you "just want to hit what you're aiming at" and that includes different distances, the math must be done. It doesn't matter what scope or bullet or rifle, they all fly in an arc.

I've noticed a lot of absolute literal meaning, going on around here... (maybe I should use more smileys)

I understand. I was Fire Controlman in the Navy. I had ballistics, projectiles, solving the fire control problem for a 70 pnd, 5" projectile, to hit a moving target at 300 knots shoved up my rear-end, 10 hours a day, 5 days a week thru 3 different schools and then doing it, in the Fleet.

I don't need to do the math. Its already been done. All I need/want, is going to the range, zeroing my rifle at a range that's going to hit consistently thru a number of different ranges, for a broad range of scenarios.

I was just trying to share, what I found to be an easy to follow and laid out video that seems to share, the same opinion you hold. A 50 yd zero.

So, let's just agree to agree on a 50 yd zero and leave it at that, OK?

 

[webfarmer]

Sighted my Eotech and irons at 50 yards which ballistically, should put the 55 grain bullet in the bull at 200 yards (or close) making it slightly high at 100. That said, like an A__, I put 150 rounds through it this weekend and rezeroed at 100 without thinking. DUH - still fun That's the gist though for what a 50 yard zero should do. Good luck!

 

[ChattanoogaPhil]

Ok... If we are going to get into the nits and picks

I've been shooting XM855
16" barrel
50 yard zero

Greatest distance above line of sight is less than 2 inches at around 140yds
Zero around 215yds
Less that 2 inches below line of sight out to 250yds

Now all this is fine and dandy... but I can't shoot offhand to this degree of accuracy with a red dot out to 250yds, the ammo will not perform to this degree of accuracy out to 250yds, and I'm not range finding with my H1.
It's a CQ battle rifle. I figure the objective is to point and click the dang thing before I get clicked!