Will I be able to zero at 100 meters?

[Nicolas Buch]

Hi guys

I have a new scope with a 20 MOA mount on its way. I'm currently shooting 300 meters primarily but want to go further - all the way out to 1000m. Which is why i ordered the SPUHR mount with 20 MOA rather than a 0 MOA (which I currently run on my old optic)

I've gone ahead and ordered a ZCO 840 (8-40x56) which has 28 mil of elevation and a 20 MOA Spuhr mount. I'm always zeroing my rifles to 100 meters and doing some quick math I was certain that this would still be possible with the 20 MOA mount. But after talking to a guy at the range yesterday i'm now in doubt. He says that I probably wont be able to get on target running a 20 MOA base at 100 & 200 meters on a .308 WIN.

Do you guys think I will still be able to zero at 100 meters?

 

[308pirate]

Hi guys

I have a new scope with a 20 MOA mount on its way. I'm currently shooting 300 meters primarily but want to go further - all the way out to 1000m. Which is why i ordered the SPUHR mount with 20 MOA rather than a 0 MOA (which I currently run on my old optic)

I've gone ahead and ordered a ZCO 840 (8-40x56) which has 28 mil of elevation and a 20 MOA Spuhr mount. I'm always zeroing my rifles to 100 meters and doing some quick math I was certain that this would still be possible with the 20 MOA mount. But after talking to a guy at the range yesterday i'm now in doubt. He says that I probably wont be able to get on target running a 20 MOA base at 100 & 200 meters on a .308 WIN.

Do you guys think I will still be able to zero at 100 meters?

I don't think so. I know so. A 20 MOA mount + a decent scope always zeroes at 100 meters/yards with room to spare. My 308 rifle has a Steiner 4-16X56 on a 20 MOA base, zeroes at 100 yds just fine, and has enough elevation travel to get to 1200 yds.

Trust your calculations. 90% of the people you speak with at a gun range have no fucking clue about what they're doing.

 

[Advokaten]

20 MOA is what, about 6 mils, with a scope that has 28 mil of adjustment, ie 14 up and down from center, you will still have plenty of travel down, if your rifle is sort of straight from the start.

This is all made from a starting point of the scope being such that is has a 14 up and down travel and not set up to have its center at say 8 up from the bottom.

That one guy at the range is always having an opinion. /C

 

[Fixr]

Hi guys

I have a new scope with a 20 MOA mount on its way. I'm currently shooting 300 meters primarily but want to go further - all the way out to 1000m. Which is why i ordered the SPUHR mount with 20 MOA rather than a 0 MOA (which I currently run on my old optic)

I've gone ahead and ordered a ZCO 840 (8-40x56) which has 28 mil of elevation and a 20 MOA Spuhr mount. I'm always zeroing my rifles to 100 meters and doing some quick math I was certain that this would still be possible with the 20 MOA mount. But after talking to a guy at the range yesterday i'm now in doubt. He says that I probably wont be able to get on target running a 20 MOA base at 100 & 200 meters on a .308 WIN.

Do you guys think I will still be able to zero at 100 meters?

I installed a ZCO527 on a 30 MOA base and had no problems achieving a 100 yard zero for 6mm CM, 308 Win, 300 WinMag and 338 LM.

What @308pirate and @Advokaten said about range advise

 

[Nicolas Buch]

Amazing thanks guys, really appreciate it. Now i'm not so worried anymore.

This is all made from a starting point of the scope being such that is has a 14 up and down travel and not set up to have its center at say 8 up from the bottom.

I thought that all scopes had their starting point in the middle of the elevation range. I checked out their technical sheet, but it does not say anything about the starting point. Just that it has 28 mil of elevation. http://www.zcompoptic.com/images/products/zc840/Technical Data_ZC840_web.pdf

 

[Advokaten]

This is straight from memory, and that is a hazy place at best, some scopes are designed to be put on a slanted/tilted base or rings and then accordingly they also have a offset so that the scopes optical centrum is not in the middle of the elevation, it is offset to make up for the base/rings,
I have a recollection that S&B PMII series have scopes like that, the really long range ones.

 

[308pirate]

Amazing thanks guys, really appreciate it. Now i'm not so worried anymore.


I thought that all scopes had their starting point in the middle of the elevation range. I checked out their technical sheet, but it does not say anything about the starting point. Just that it has 28 mil of elevation. http://www.zcompoptic.com/images/products/zc840/Technical Data_ZC840_web.pdf

Just spin the turret from one extreme to the other and count yourself.

Just be aware that what you actually get may be off a click or two from what is advertised. That's the difference between theory and practice.

 

[308pirate]

This is straight from memory, and that is a hazy place at best, some scopes are designed to be put on a slanted/tilted base or rings and then accordingly they also have a offset so that the scopes optical centrum is not in the middle of the elevation, it is offset to make up for the base/rings,
I have a recollection that S&B PMII series have scopes like that, the really long range ones.

Never heard of that before.

 

[GIXXER2000]

I have a Zcomp 5x27 on my Cadex 375ct The top rail has 40MOA and the ERA TAC mount set at 10 MOA so with total of 50 MOA total I can zero at 100 yard

 

[FrozenFingers]

You'll be fine

 

[Nicolas Buch]

Amazing, thanks for the help guys

I did think to myself that the guy at the range didn't know what he was talking about, but then again i'm pretty new to this myself.

I reached out to ZCO yesterday to hear them out if they offset their scopes elevation range and this was their reply (might help someone else out at some point):

Our riflescopes are delivered in the mechanical middle position, it means for ZC840 i.e. 14mil up / 14mil down.

 

[pineoak]

Never listen to that guy ever again. Smile and be polite, but he has no clue.

20 MOA, and to a lesser degree 0 MOA are the standard mounting for scopes (front of scope should tilt slightly DOWNWARD)

 

[acudaowner]

anyone else yes no problem you only god knows .

 

[hlee]

Guy at range- “Hey yah….” “Hey yah…”
Me- “Sorry. I’m wearing ear pro, and listening to loud music. Can’t hear you.” Goes back to shooting.

 

[HeavyAssault]

My rifle has a 20 MOA base. With a new scope I ran the adjustment all the way Down to the bottom. Came up 10mil from the bottom. On a 100yd range when firing to zero I needed another .6mil UP. Rounds impacting where I want them. Done. Yes, I'll still be fine tuning the adjustments but now it's adjusting .1 MIL here or there.

I'm not sure why anyone would tell you can't zero at 100M with your setup. All you need to do is know the ballistics for your round at 100M for whatever range you want to have as your true zero.
I.E.: If your round ballistics show 2" high @100M for a dead 0" @300M then shoot using a POA (Point of Aim) on your 100M target dead center. Just adjust your scope to bring your impacts up 2". Sure, you would want to verify this on a true 300M target.

I want to say it was told to me: "The shooter generally wants to shoot longer distances, not shorter distances after you have Zeroed the scope/rifle. Why are you not setting up the scope to give you the most adjustable travel UP. Cause it's rare when you need to adjust Down."


This is my 100yd ZERO. I hold the scope reticle center on the red dot (3/4" in diameter). As long as my rounds are impact at 1+" high, maybe 2+"high, I'm happy cause that's telling me I should be stacking rounds on top the red dot at 200yds (more like 225-250 yds depending on ballistics). Yes, I need a longer target range to verify.

 

[GIXXER2000]

I a Zcomp 5-27 on my 375ct the rail is 30 moa and I use a TAC ERA adjustable mount. I add 10 more moa so a total of 40 moa and can zero at 100 yards. the scope has 34 mils of travel and I still could go down 1.7 mil if needed. you should be fine.

 

[Aftermath]

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Edit for OLD THREAD

 

[Slides]

For anyone playing at home, pretty much any 30mm tube scope will zero at 100 on 40MOA base or base/mount combination. With usual POI/velocity/scope height 20MOA base will only put you something like 1 or 2 MIL low of elevation centre which is a waste of internal elevation. TBH I not sure why a 15, 20 or 30MOA cant wasn't standard on narrow tube scopes historically.