Scope zero

[Nuclear Worker]

Maybe this is a dumb question but I don't know the answer. So you get a new scope and mount it on your rifle. Let's say it has 80 MOA adjustment. If you do your zero from where your Elevation turret was coming out of the box. How do you know that it's not turned up half way already? Or do you turn it down as far as it will go and then zero? If it was turned up halfway from the factory? Wouldn't you lose half of your MOA adjustment? Hope this makes sense.

 

[Csafisher]

Doesn't matter where is turned. Zero it. Assuming you have no cant in your rings/base and you don't zero at some really close or far distance you should be close to the half mark (40moa in your example).

 

[cajun]

When you get your scope mounted you should bore sight then go zero it. It's going to be what it is. You cant really run it down to the bottom of it's travel and then try and zero it. Several things will affect how much travel you have. Rail, ring height. Most scopes come out the box set at or close to center of travel range. So if you have 80 moa range that's total. So if your close to center you would have 40 moa up and down.

 

[Hand Skills]

Lots of guys use canted rails to get more elevation out of their scope.

20moa rails are pretty common, and would allow for theoretically 60moa UP instead of 40 in this example.

 

[Nuclear Worker]

So apparently you just run it all the way up all the way down and divide by 2. In my example you would start at 40 MOA.

 

[dfanonymous]

So apparently you just run it all the way up all the way down and divide by 2. In my example you would start at 40 MOA.

That's called a mechanical zero.
It irrelevant to a 100y zero. When you add a scope base with moa, then you move the erector even further out of that mechanical zero.

That said, it's not a requirement to start at a mechanical zero. There's a variety of ways to do it. Some more efficient than others.

If it's a new gun, and a new scope, I like to start at 25 yards on a 1 inch square. I shoot, and move the reticle to the bullet hole a few .1 of a mil high. 1 shot. Second shot I verify is a little high, say the top of the 1 inch square.

I move back to 100 and shoot again, then move the reticle to the shot without moving the rifle. Zero'd.

I've been doing this for a long time, so it's a shortcut I myself can do. I can keep the rifle steady, and I can repeat shots fairly well.
For others who might not have as solid of a foundation and technique, shooting a group and zeroing to the average might be the better way.

 

[FEENIX]

Members above pretty much got it covered.

 

[AZShooter]

If you wish to verify that the scope's reticle is mechanically centered, place the front objective on a mirror or if already mounted place a small mirror over objective end. If it is centered you will see one crosshair. If not centered you will see a double image. Rotate elevation and windage till the two crosshairs are superimposed and it will be mechanically centered.

 

[cohunt]

If you wish to verify that the scope's reticle is mechanically centered, place the front objective on a mirror or if already mounted place a small mirror over objective end. If it is centered you will see one crosshair. If not centered you will see a double image. Rotate elevation and windage till the two crosshairs are superimposed and it will be mechanically centered.

Wow, cool- never thought of that--- but none of my scopes are mechanicly zeroed so it is pretty much a moot point.

 

[cajun]

First of all do some math. If 40 moa is not enough just put a 20 moa rail on it. Otherwise just bore sight it and go zero it. Putting the scope at it's mechanical center before you zero it does nothing. Your zero is going to be what it is. Most of the time with a normal height above the barrel you should wind up close.

 

[swampbug]

Lots of guys use canted rails to get more elevation out of their scope.

20moa rails are pretty common, and would allow for theoretically 60moa UP instead of 40 in this example.

But the final scope travel is important to think about. I have a 6.5 CM with a 4x20 ZCO on it and a 20 MOA rail. For all practical purposes, I have enough scope travel for easily out past 1,000 yards but there is a limit to distance bc my scope tops out. The reticle will give some more hold overs. But I'm just saying, you need to think about what your needs are and how that affects rail cant and scope height.

 

[xsn10s]

That's called a mechanical zero.
It irrelevant to a 100y zero. When you add a scope base with moa, then you move the erector even further out of that mechanical zero.

That said, it's not a requirement to start at a mechanical zero. There's a variety of ways to do it. Some more efficient than others.

If it's a new gun, and a new scope, I like to start at 25 yards on a 1 inch square. I shoot, and move the reticle to the bullet hole a few .1 of a mil high. 1 shot. Second shot I verify is a little high, say the top of the 1 inch square.

I move back to 100 and shoot again, then move the reticle to the shot without moving the rifle. Zero'd.

I've been doing this for a long time, so it's a shortcut I myself can do. I can keep the rifle steady, and I can repeat shots fairly well.
For others who might not have as solid of a foundation and technique, shooting a group and zeroing to the average might be the better way.

That's how I do it unless I'm at a busy range like when I zeroed my 7mm RM. I generally zero my rifle @ 100 yards and then figure out where the zero is in my elevation range. After that I figure out what moa rail I want if any. Some rifle's exterior dimensions are off slightly thus changing what moa rail you might want.

 

[Bucklowery]

Your scope is mounted blank inches above the bore. That has to be corrected in the scope during the zero process. That is where you loose some of your elevation adjustments

Thanks

Buck

 

[crkckr]

I like to start things off with a mechanical zero, then bore sight on something quite a ways out, maybe a tree top or something (works ok with no wind!) several hundred yards out. The mechanical zero would let me know if I needed to add a different mount. It also lets me know how well the scope mounting went in the first place... if it's way off on the bore sight, I go back and look at the mounting process and check alignment and such.

Then I try a 25 yard shot on one of my own designed targets. I will check a ballistics computer well beforehand to find my Point Blank Zero Range and exactly where I should be hitting at 25 and once there, move to 100 yards (the extent of my range, unfortunately). There is always some amout of adjustment to fine tune things from there but I've found that once "on" at 100, it is generally on out to 300 for me. Beyond that is guessing because I've never been on an actual range that went out that far! I've gone out in the wild and used a range finder out to 400 but just never had more room than that. I only have 4 rifles that could exceed that and since I don't hunt much any more (and generally couldn't go out anywhere near that where I might hunt) I don't bother. Arrangements could be made if it ever became necessary but for the way things are for now, it serves me well.
Cheers,
crkckr