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Hi Guys

I have asked this question on another site and was wondering what the concensus on this site would be.
I have a scope which has a listed 15 Mils of adjustment. However it has a total travel of 18.6 Mils from left to right. So I would assume its mechanical zero is 9.3. I.e 93 clicks from centre either side. (Not wanting to name the make in case this biases opinion) How much when zeroing the windage would be acceptable for the scope to be offset from mechanical zero. Plus how much error is acceptable for the rings and rail combined. Shooting out to 1100Yards.

Thanks Lee

Sorry mods put in wrong category. No wonder my accuracy is bad if I missed putting it in the right one. Can you please put in Full Bore.

Try this.......then the windage and elevation should be in the middle of their travel.

https://www.youtube.com/watch?v=-A3GwfB0Yg8

Pete

Have just tried this and when I put the mirror up against the scope it all goes black and I can't see any thing. I don't have illuminated reticles.  

Just tried with a cheap scope and I can just about see the double cross hairs but on my higher mag scopes with the mag turned out it is just black in the centre. Plus they have coated lenses and they may stop the reflection?

I've done it with Sightrons, Vortex, and an IOR without any problem.......the trick, as the guy said, is to do it somewhere with a lot of ambient light.
I used a second pair of hands aiming a spotlight at the mirror around where I was holding the scope. It's a faint but unmistakable image.

Pete

Ok. Will give it another go tomorrow with the aid of a work lamp.

Assuming you are shooting a 308 you are going to need around 11.5 mRad to get to 1100 yards or around 9.5mRad if you are shooting a 6,5mm. So in theory at least, you have the elevation to get to 1100 or even 1200 yards on a warm day. So forget your 'scope true zero at this stage and get out and shoot 3 shots at 100 yards to zero the rifle, you can even bore sight at this stage. Make a note of your elevation setting and count how many mils you have left to the max it out. If you have a zero MOA rail and a reasonable set-up you should get there OK.

BTW - sorry about the mix of angular units.

Now, what is far more important to me is the mechanical zero of the 'scope. When I wind it down I want it to bottom out on 100m plus 1 click (1cm) and to get this on my Accuracy International with a 4-16PMII I need 28 minutes of incline on my rings. This gives me the maximum use of the somewhat limited range of elevation I have and allows me to shoot at 1100m on target on all but the coldest days where I have to aim off slightly.

Checking the 'scope is zeroed is great however somewhat irrelevant if the 'scope, rings and rail were fitted correctly. For windage if the drum has been off simply count the full range of clicks and divide by 2 and put your drum there. Oh and if you are struggling with the ghost reticle and mirror trick just hold the mirror off by a few mm to let some light in.

Ovenpaa
Thank you for your input. The error for my scope when fitted is 49 clicks left with 1 scope and 29 with the other. When set to mechanical zero.
I have again tried the mirror method seems direct sunlight is better than 2 spot lights. The results are with scope 1 it is perfect both mechanical zero and optical zero are the same. Scope 2 is off by 3 clicks to the right from mechanical zero.
What now comes into play. Is why there is 20 clicks difference in the same 1 piece mount between scopes 1 and 2 if the only error between scopes is 3 clicks right ? Or is there something else that I am not factoring in.