Thread: Scope adjustment issues

The other day I was re-zeroing in a scope after swapping from one rifle to another. Used a laser bore sighter first to adjust scope. Took 1 shot at 50m to check i'm on paper, hit level with bullseye and 2" to left. moved target to 100m and fired a 3 shot group, 4" to left and still level with bullseye. Adjusted windage to the right 4 moa and took a second 3 shot group, group was still at 4" to left but elevation dropped 4". WTF. I adjusted 4 moa to the right again, fired another 3 shot group and hit 2" to the left of and "2 under the bullseye. Adjusted another 4 moa to the right and up, fired another 3 shot group and hit 1/2" to the left and level with the bullseye. ???. It got too frustrating so I left it there and took my old shotty and new old dog for a hunt, sun was too intense for both of us so didn't get far and shot nothing.
Can anyone tell me what the hell was up with my scope? never had this issue when zeroing in on the last rifle
Thanks

1. What scope?

2. Laser bore sighters are worse than taking your bolt out and looking through the rifle (assuming it's a bolt action?)

3. How have you got it mounted? A few pics > thousands of words

You may have run out of windage adjustment and are at close to the limit of your elevation.

Cranking the elevation down freed up a bit of your windage. Bit hard to draw a diagram but visualise a circle/clock and the centre of the cost hair is hard against the edge of the circle at 4 o'clock. Adjusting elevation down would move the reticle slightly into open space giving you a wee bit more windage.

It would also seem strange though if you've reached the limit in one direction or other that the adjustment didn't just stop solid. Having said that I have an older Leupold that caught me out on the elevation - it just continued to click at max elevation with no change.

Try optically centering the reticle and start again. Either by winding full the other way and counting the clicks and then come back half, or by the mirror method (google it). Throw the laser away and just use eyeball bore sighting.

Or your scope has just plain failed internally.
Strange if it was OK on the last rifle.

Do you know the rifle/shooter can shoot?

No help but reminds of of when i answered a similar call for help with a mate who'd decided to get into shooting a few years ago, inspection revealed he'd mounted the scope 90degrees anti clockwise so had ended up with the windage dial on top and the elevation on the left side, suffice to say it was a relativity easy fix and i still get good mileage out of reminding him....... he'll be turning red reading this

Originally Posted by Grasshoppa

No help but reminds of of when i answered a similar call for help with a mate who'd decided to get into shooting a few years ago, inspection revealed he'd mounted the scope 90degrees anti clockwise so had ended up with the windage dial on top and the elevation on the left side, suffice to say it was a relativity easy fix and i still get good mileage out of reminding him....... he'll be turning red reading this

I don't like making assumptions but I also wondered if this could be the issue.

What size were the groups ?

Originally Posted by RUMPY

I don't like making assumptions but I also wondered if this could be the issue.

No. Scope is mounted properly.

Originally Posted by Bagheera

What size were the groups ?

2" at 100m, wasn't my best groups with that rifle, ammo I was using wasn't the best neither, all I had on hand.

Originally Posted by Three O'Three

No. Scope is mounted properly.

Mounting the scope 90 degrees anti clockwise won't cause an issue, except an initial mind bender. Assuming windage and elevation have similar amounts of travel and the reticle is a simple crosshair. I know a guy that did exactly that as his windage turret was taking a pounding from ejected cases.

Originally Posted by zimmer

Mounting the scope 90 degrees anti clockwise won't cause an issue, except an initial mind bender. Assuming windage and elevation have similar amounts of travel and the reticle is a simple crosshair. I know a guy that did exactly that as his windage turret was taking a pounding from ejected cases.

im not the only one then .......had a winy top eject 94 with a side mounted offset scope which i turned the scope 90 so the turret wouldnt take a hammering......worked well and didnt obscure the iron sights

So, in theory youve adjusted for 12MOA Right and 4 MOA up but the group has moved 3.5” Right ?

The most important thing is your rifle is now permanently sighted in.

Things i have done myself, in order of likeliness:
Wandering zero due to bedding or looseness.
Underestimating actual group size by firing too few shots per group. Next time use 5 shot groups before adjusting.
Scope adjusts less than it says. 1MOA on dial not actually 1” on target.
First adjustment of 4MOA was on elevation turret not windage.
Scope sticking and will later flick across lots to make up for it.
Wind
End of adjustment range as described above.
Different ammo ?

This sort of pfaffing around is pretty normal when sighting in.
Youve only fired 12 shots and now its spot on. No worries mate.

Originally Posted by Bagheera

So, in theory youve adjusted for 12MOA Right and 4 MOA up but the group has moved 3.5” Right ?

The most important thing is your rifle is now permanently sighted in.

Things i have done myself, in order of likeliness:
Wandering zero due to bedding or looseness.
Underestimating actual group size by firing too few shots per group. Next time use 5 shot groups before adjusting.
Scope adjusts less than it says. 1MOA on dial not actually 1” on target.
First adjustment of 4MOA was on elevation turret not windage.
Scope sticking and will later flick across lots to make up for it.
Wind
End of adjustment range as described above.
Different ammo ?

This sort of pfaffing around is pretty normal when sighting in.
Youve only fired 12 shots and now its spot on. No worries mate.

What really got me was when adjusting the windage the first time, it didn't move but the elevation dropped instead

It's quite common for non dialed scopes to "stick"
Because they dont get the use.

Best practice for a set an forget type scope IMHO is

If you have to adjust out(anti clockwise one most scopes but not all) on a scope that never moves(not dialed) go a full turn out.....tapp the scope then wind back into whatever adjustment is required.
Scopes and especially the cheaper or just old can stick the adjustment while you twiddle dials and waste ammo.

If it's an older scope and not being dialed I suggest backing out both elevation and windage at least a turn if available and giving the rifle/scope a few gentle but solid taps in both up and down motions.
The adjustment is driven in by a thread but only returned by a spring.....which can stick.
So imo it is best to start out with an unknown by winding out adjustments and working your way back into zero as you have a positive adjustment driven by a thread rather than relying on a spring in the scope to adjust which may not do it for 3 shots then all of a sudden move to your set point....and by now you already changed the scope dial cos nothing was moving then all of a sudden it went too far.

Check the set of mounting rings.
If everything is well placed, with the corresponding tightening. Adjust your scope to 25 meters, no more, depending on the caliber, the second zero will be 170-180 meters.
Once calibrated at that distance, take the shots at 100 meters, to see how you group your rifle.