Centering a scopes cross-hair

clivej

OK so this is what I do before putting a scope on any gun and to check that a new scope's cross-hair is in the centre.
Scope shown is a Nikko Night-Eater 8-32 x 60 AG IR
Why:
A. Gets you on paper quicker.
B. You know the scope is true.

1. Make up a "Vee" block. 3 bits of timber with a V cut out and clamp to a table. Put a plumb line up or use a vertical object - Phone pole edge, Edge of a house about 30m-50m away.




2. Put the scope on the Vee block and line up the windage cross-hair with your vertical line. Now rotate the scope through 180 degrees without moving the Vee block. Note how much out of line the cross-hair is with the vertical line and adjust the windage turret halve way to close up the diffference. Line up with the vertical line again and repeat until when you rotate through 180 degrees the cross-hair remains on the vertical line.




3. Put the scope in the Vee block so that the elevation cross-hair is in the vertical, on it's side, and repeat as above until the elevation cross-hair is true. When this is completed you will be able to rotate the scope through 360 degrees and the cross-hair will remain on the one spot. The cross-hair is now centered and true.




4. Now fit your mounts to the gun.
Here is my CZ Varmint 223. The dovetails are 15mm and I have used a 15mm to 11mm adaptor from the Sportsmatch range. I used Sportsmatch 30mm medium high mounts with a 11mm dovetail here. Just tighten up the set screws enough to hold the scope in the mounts but can still rotate in the mounts.
You can see the white dot turret indicater that I will use to level the scope in the monuts.




5. Using a credit card I now line the gap in the mounts up with the turret white dot from both sides. This will level the scope in the mounts. Only tighten up the set screws enough to hold the scope in the mounts and without crushing the scope tube.




Finished scope on my CZ Varmint 223 ready for the range.
At the range I dialed in a bullet drop of 2" + 2 1/4" for the scope centre from the bore and fired a 5 round test shot group -- using Remington UMC HP 50gr 223 ammo @100m. It was on paper @100m and only 1" right and 4" low. This I put down to the mounts being out just a little. The group was just above MOA at 1 1/2" but tightened up as I got more used to my new CZ Varmint.

bunny shooter

Clive is your cheek/head a bit far off the stock with this setup?

clivej

By set up I take it you mean is the scope to high!
I only went out for the first time in the field today and I must say that it falls just about OK. If anythng the scope could be a little farther forward but the turrets hit the mount so I can't do that at the moment. I may get an extended reach front mount sometime later.
The gap under the front objective is about 8mm so thats all it can come down anyway. I had this scope on my CZ 22lr Style and the gap was 5mm at the front objective and I found that was OK to use for me.

Vegeta

Did you have much adjustments to make Clive?

After it was optically centred did you have roughly equal moa up, down, left and right?

If the scope is too high have a look at the bear tooth comb raising kit.

Excellent post by the way

riflehunter77

Great bit of info there clive, got to admit iv not heard of setting up and zeroing a scope like that before. Its good to see fresh new ideas. Rifle looks well to clive enjoy and safe shooting

clivej

Vegeta wrote: »

Did you have much adjustments to make Clive?

After it was optically centred did you have roughly equal moa up, down, left and right?

If the scope is too high have a look at the bear tooth comb raising kit.

Excellent post by the way

I was on paper @100m and 1" to the right and 4" low not bad as a new set up goes. I'd say that the mounts were out by that much.
I'm very pleased with the new CZ Varmint and how well it shoots.

ianoo

exellent post clive..
thanks for giving me something else to melt me head with

ian

Trojan911

Great post Clive.... Something to try later....

Vegeta

clivej wrote: »

I was on paper @100m and 1" to the right and 4" low not bad as a new set up goes. I'd say that the mounts were out by that much.
I'm very pleased with the new CZ Varmint and how well it shoots.

Good stuff

Did you have to adjust the turrets much to get it optically centred or was it pretty close from the factory??

clivej

Vegeta wrote: »

Good stuff

Did you have to adjust the turrets much to get it optically centred or was it pretty close from the factory??

Elevation at zero and windage was 2 clicks left.
That scope is good in that I centered the scope back in may when I first got it and it was elevation at zero and windage was 2 clicks left back then.
Since then I have been up and down with both turrets at the range and when I again centered the scope last weekend for this post and to put the scope on the new gun it returned to exactly the same turret points for centre. Just as it should have.

thehair

well done clivej you have very good info for people and i have just learner
a very good way to centre a scope crosshair top class post clivej thank you
very much from steve:) you would make a great MOD for new people to the sport of shooting;)

fish slapped

Great post Clive , well done but just one question, would you recommend Gloss or emulsion?:D . the 60mm bell is quite a size on the scope.