A scope's mechanical zero....

[Timmis2]

Do most scope manufacturers design their scopes for their mechanical zero to be in the middle of the elevation range? I think the rule of thumb when zeroing in a scope on a rifle for the first time is to set the windage and elevation to the center of it's range and make adjustments from there. It would seem to me that scope manufacturers would account for the need for the most adjustment for bullet drop, and mechanical zero at the middle of the elevation range would leave a lot of clicks lost to adjustment for bullet rise which there only seems to be a need for a few MOA when shooting at close range like when a deer walks up to your tree stand to admire your choice of laundry detergent.

 

[NZ_Fclass]

Well, yes. But to be sure, it's always worth counting the clicks - or at least the MoA from top to bottom and side to side and establish the correct zero. I recently bought a used scope, of a not well known Japanese brand, Vixen. Had all the hallmarks of good glass, 34mm tube 8-30x etc etc and a decent retail price. Counting the windage, it seemed to have little to the left adjustment. No info on the web, oddly. However, on removing the turret, I discovered a zero stop mechanism. Once removed, the scope works fine. Why do we need a windage zero stop? I'm guessing that Vixen use the same mechanism for both directions. BTW, it's a cracking scope and sitting on my 223 FTR gun.

 

[gdbleb]

I think March has a reticle that looks to address this ELR issue. No idea what relation there is/isn't of reticle zero to mech zero.

 

[6BRA]

Post 23 one of the most valuable reads I have seen.

Thread 'Optically centering scope?'

May 18, 2011

I've been trying to learn about optically centering my scope, which as I understand it is basically ensuring that my scope is pointing directly in line with my bore (left to right), eliminating drift along the range. For example, if my scope is pointed slightly RIGHTWARD compared to my bore, if I'm sighted in at 200yrds, then at 50yrds, the shots should strike to the right of my POA, and then at 500yrds, the POI will be slightly to the left of my POA.

To account for this, I have heard you need to optically center your scope, then adjust your rings/mounts to ensure lateral alignment...

• Varminterror
• Replies: 27
• Forum: Scopes, Optics, LRFs, Spotters, BoreScopes

 

[JEFFPPC]

Do most scope manufacturers design their scopes for their mechanical zero to be in the middle of the elevation range? I think the rule of thumb when zeroing in a scope on a rifle for the first time is to set the windage and elevation to the center of it's range and make adjustments from there. It would seem to me that scope manufacturers would account for the need for the most adjustment for bullet drop, and mechanical zero at the middle of the elevation range would leave a lot of clicks lost to adjustment for bullet rise which there only seems to be a need for a few MOA when shooting at close range like when a deer walks up to your tree stand to admire your choice of laundry detergent.

Your making something simple hard. Count the clicks and set it in the middle. Then use the Burris Signature Rings with inserts to get as close as possible to Zero with out using the internal scope adjustments. If you do a lot of up clicking you can even cheatbthe system so to speak by seatting you zero a bit low in your internal adjustment range. Very important in the airgun game but applies well to powder burners. Remember this because a lot of guys get confused setting up these rings, " Point the front of your scope tube(objective lense) opposite the way you want the gun to shoot".

 

[Timmis2]

Since I posted the question, I received a short and simple explanation from an optics manufacturer salesperson that a scope's mechanical zero is in the middle of the range of windage and elevation turret turns because the middle has the most optic quality. I suppose this means that when using a scope rail with a 20-50 MOA cant but shooting at 50 yards you may sacrifice optic quality, but a longer distances optic quality improves.

 

[ELR LVR]

Do most scope manufacturers design their scopes for their mechanical zero to be in the middle of the elevation range? I think the rule of thumb when zeroing in a scope on a rifle for the first time is to set the windage and elevation to the center of it's range and make adjustments from there. It would seem to me that scope manufacturers would account for the need for the most adjustment for bullet drop, and mechanical zero at the middle of the elevation range would leave a lot of clicks lost to adjustment for bullet rise which there only seems to be a need for a few MOA when shooting at close range like when a deer walks up to your tree stand to admire your choice of laundry detergent.

Depends on your discipline
for 100 yd shooting, which MOST scopes are designed for
Most everything is near center.
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This is not what you want for Long Range though
which is why many scope makers offer high Elevation MOA adjustment ranges
and why we have things like 20 MOA bases
What I do for Long Range is
Bottom out the elevation
then use whatever MOA base I need to bring it close to 100 yds
could be 20 could be 40 or in between
For Long Range you want the most windage adjustment and can only get that when your elevation is in the middle of its adjustment range

 

[6BRA]

Post 4 to attached link post 23. Centering only applys to objective lens and parallax is far more important as magnification increases parallax increases.Eyepiece ocular lens only has 1 job which is to focus on reticle. I still think centering objective for desired yardage is preferred. Burris XTR inserts can allow you to take a 20 moa base back to zero moa or opposite to 40 moa.or just about about anywhere in between.