Is my scope Broke ?

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GSells
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Is my scope Broke ?

#1 Postby GSells » Fri Mar 22, 2019 10:33 pm

Ga day all of my shooting fraternity! Well since 1000 yds December last year I’ve been battling vertical. A few things that has been me . But today when I was training. After live firing , I was dry firing and noticed that the cross hairs would vibrate or minutely bounce on the target I was aiming at when I pulled the trigger!

Question ? Should I send my NF Comp away and get checked ? I’ve just gone from shooting well to a Fetal position . I’m very much the last one to blame my gear except for the 280 ai lol.

Below is 300 yds with my Bart 284 w last Saturday! I had 1moa vertical. But it grouped ! I couldn’t hit the middle for love nor money!

I would adjust and then it would go over the top or something like that . I then got it in the x ring next shot from memory went low in the five ring . Adjusted and out over the top ! Anyway the pic tells the story.
2DCC8836-58D7-4A66-A26A-E492B5E4F889.jpeg
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Frank Green
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Re: Is my scope Broke ?

#2 Postby Frank Green » Fri Mar 22, 2019 11:10 pm

That is one test you can perform. Dry firing. If you see the cross hairs bouncing than I'll say the scope is not holding zero. I've seen it a couple of times my self and it was the scope.

Another thing you can do to check for tracking is while looking thru the scope at a horizontal or vertical object with a hard line for reference. While viewing thru the scope move the windage knob full left and full right. If you see the crosshairs dipping up or down while doing this (same test for vertical) again the scope is not tracking. I've had this happen on two different Leupolds.

In a 4 man team match one of my shooting buddies had a 10-60x March go sour on him. Had wild shots that couldn't be explained. The bulk of them vertical. In between relays we checked it by dry firing and the cross hairs where bouncing. We sent the scope back for repair.

Later, Frank
Bartlein Barrels

GSells
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Re: Is my scope Broke ?

#3 Postby GSells » Sat Mar 23, 2019 6:16 am

Frank Green wrote:That is one test you can perform. Dry firing. If you see the cross hairs bouncing than I'll say the scope is not holding zero. I've seen it a couple of times my self and it was the scope.

Another thing you can do to check for tracking is while looking thru the scope at a horizontal or vertical object with a hard line for reference. While viewing thru the scope move the windage knob full left and full right. If you see the crosshairs dipping up or down while doing this (same test for vertical) again the scope is not tracking. I've had this happen on two different Leupolds.

In a 4 man team match one of my shooting buddies had a 10-60x March go sour on him. Had wild shots that couldn't be explained. The bulk of them vertical. In between relays we checked it by dry firing and the cross hairs where bouncing. We sent the scope back for repair.

Later, Frank
Bartlein Barrels

Thanks Frank , I have a NF NXS in mils I’ll throw on and take the NF Comp off and send it away . I’ll shoot some groups with the NF nxs . It’s just I used to at 100m shoot consistent one hole groups in my sleep. And now wild shots like a minute high or low show up . Same on target down range . I’ve been blaming myself ( which is where I always look first ) . It has been doing my head in ! Maybe also the 280 ai was ok ! As the problems transferred to my Bart .284w which is a proven winner and even at 300 yds I’ve had a minute vertical, 2 moa with correction to try and find the middle!

I’ve had High end scopes go on me before , but they were more dramatic and easier to identify!
Wow I hope this is really it as I’ve been going around in circles!! #-o
Look NF scope comp is a great scope but this one has done a lot of work

ShaneG
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Re: Is my scope Broke ?

#4 Postby ShaneG » Sat Mar 23, 2019 8:22 am

Graham
Do the test Frank advises above but also exercise the elevation / windage turrets to their extreme several times.
Then box test it at 100 or 300 - just make sure you have a perfect aim point without mirage
I had a Comp giving elevation in US a couple of years ago.
Box tested at 100 yards and had 1 moa groups
Vicki mentioned the turret exercise that night and carried it out - next morning same load / range I gave up after 3 shots in each corner - rifle back shooting approx .2 moa!
I still sent it back to NF though

KHGS
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Re: Is my scope Broke ?

#5 Postby KHGS » Sat Mar 23, 2019 8:30 am

I have always recommended that at the end of the day's shooting to wind your scope to it's 1000 yd setting to "ease springs". Think of it the same as de-cocking your bolt. Elementary my dear Watson!!!!
Keith H.

Rich4
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Re: Is my scope Broke ?

#6 Postby Rich4 » Sat Mar 23, 2019 8:34 am

Hi Graham, I would have a close look at your rest too before you post the scope away, changing to the nxs will show it too, remember I said I got a weird vibration when I used it? I’ve since made new feet and plate for my rest and I don’t feel that at all, cheers Rich

pjifl
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Re: Is my scope Broke ?

#7 Postby pjifl » Sat Mar 23, 2019 8:43 am

You can make a Collimator of sorts using another Riflescope if you are interested.

The basic principle is to have one scope look into another face to face. It is not up to a dedicated Collimator but it does work.

Take a substantial piece of RHS steel and screw onto it two Pic Rails for the scopes. Then after adjusting so the X hairs line up, do some tapping or adjusting the knobs back and forth looking for inconsistencies or a non returning sight picture. Also Zooming back and forth - especially after Zooming to the end of the range looking for a POA change. You can detect better than 1/8 min problems.

Although it may look like the Graticule is moving if you find a problem, that is extremely unlikely. A second focal plane Graticule needs to move a relatively huge amount because of the inherent magnification within the scope Zoom mechanism. Far more likely is the Zoom/erector mechanism has a loose lens or poor mechanical tracking because of some back and sideways backlash. Or the Adjustment knob tracking is defective. These need truly minute tolerances.

The above Jury Rig Collimator can pick up many problems but it is hard to make it pick up all problems. You really need a more rigid setup which you can hit quite aggressively with a hammer in various directions. What it will do, however, is quite successfully investigate tracking errors if they exist. Small intermittent errors from severe recoil can be extremely hard to pick up.

BTW, the paranoia many have about marking the tube of a Riflescope by overtightening mounting rings is a myth. The way a Riflescope is built, the outer tube is not in contact with the critical moving parts. POA change will be due to some unwanted sideways movement of a lens or Zoom/Erector sliding parts or Adjusting Knobs. A small amount of back and forth backlash also has no effect.

Peter Smith.

GSells
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Re: Is my scope Broke ?

#8 Postby GSells » Sat Mar 23, 2019 8:53 am

Rich4 wrote:Hi Graham, I would have a close look at your rest too before you post the scope away, changing to the nxs will show it too, remember I said I got a weird vibration when I used it? I’ve since made new feet and plate for my rest and I don’t feel that at all, cheers Rich

Hi Rich , welcome to the forum! Yep I’ll keep that in mind ! I think when we shot that 900 yd fly shoot in Chinchilla a month ago again huge elevation and heart break too! One think is for sure , I have elevation problems that are very much out of the normal! I’m not saying all of it is gear ! But I use to not think about actually shooting and just worry about the conditions! Now I’m second guessing myself! So I’m pretty sure it’s the scope intermittently playing up .
Changing scopes and sending the comp away will cross that variable of the list !

But it has been terrible for me ! I’ve never been short of confidence in my abilities and this trial has sorted that out lol! I’ve even stopped shooting prs till I get my main decipline back to where it was !
I really hope this is it as it would explain a lot of things ! [-o<

GSells
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Re: Is my scope Broke ?

#9 Postby GSells » Sat Mar 23, 2019 9:03 am

pjifl wrote:You can make a Collimator of sorts using another Riflescope if you are interested.

The basic principle is to have one scope look into another face to face. It is not up to a dedicated Collimator but it does work.

Take a substantial piece of RHS steel and screw onto it two Pic Rails for the scopes. Then after adjusting so the X hairs line up, do some tapping or adjusting the knobs back and forth looking for inconsistencies or a non returning sight picture. Also Zooming back and forth - especially after Zooming to the end of the range looking for a POA change. You can detect better than 1/8 min problems.

Although it may look like the Graticule is moving if you find a problem, that is extremely unlikely. A second focal plane Graticule needs to move a relatively huge amount because of the inherent magnification within the scope Zoom mechanism. Far more likely is the Zoom/erector mechanism has a loose lens or poor mechanical tracking because of some back and sideways backlash. Or the Adjustment knob tracking is defective. These need truly minute tolerances.

The above Jury Rig Collimator can pick up many problems but it is hard to make it pick up all problems. You really need a more rigid setup which you can hit quite aggressively with a hammer in various directions. What it will do, however, is quite successfully investigate tracking errors if they exist. Small intermittent errors from severe recoil can be extremely hard to pick up.

BTW, the paranoia many have about marking the tube of a Riflescope by overtightening mounting rings is a myth. The way a Riflescope is built, the outer tube is not in contact with the critical moving parts. POA change will be due to some unwanted sideways movement of a lens or Zoom/Erector sliding parts or Adjusting Knobs. A small amount of back and forth backlash also has no effect.

Peter Smith.

Thanks Pete for the input . I wish I lived down the rd from lol!
In a way Pete . When I was aiming at a bullet hole at 100 m , and seeing it bounce is that the same in a weird way ? Also I think for me alone out west here , rigging up a basic scope test rig is maybe beyond my skill level .

But it has been strange ! Like after having a break from top level shooting . I came straight back at Northarm opm and Won the 300 m shoot with no training or prep work !! Now I’m thinking of everything before pulling the trigger. Far from the 2 moa group shot last Saturday at 300 yds .

bruce moulds
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Re: Is my scope Broke ?

#10 Postby bruce moulds » Sat Mar 23, 2019 12:54 pm

graham,
I sent one back to NF once in a similar mental state to you.
it came back with a report saying nothing was wrong and they had to do nothing.
but the priblem had gone away :roll: =D> .
bruce.
"SUCH IS LIFE" Edward Kelly 11 nov 1880
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GSells
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Re: Is my scope Broke ?

#11 Postby GSells » Sat Mar 23, 2019 1:31 pm

bruce moulds wrote:graham,
I sent one back to NF once in a similar mental state to you.
it came back with a report saying nothing was wrong and they had to do nothing.
but the priblem had gone away :roll: =D> .
bruce.

That must be frustrating! maybe they are just trying to protect the brand ? But in my case , when u can actually see the cross hairs move when taping the side of the scope or when u dry fire , that must be a cause for thought and reflection? .

Anyway it still has to be proven!! And also the 280 ai may have been wrongfully accused?? I’m still going Saum and like I said retune to K.H.G.S recommended speeds and very long barrel life if so (280 ai ) !

Rich4
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Re: Is my scope Broke ?

#12 Postby Rich4 » Sat Mar 23, 2019 1:43 pm

There’s too many movable things between your scope and target for that to be reliable, what peter is suggesting is essentially a long Picatinny rail where there can be no movement between the two, not an engineering masterpiece.
However you must still have another scope you trust implicitly #-o

pjifl
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Re: Is my scope Broke ?

#13 Postby pjifl » Sat Mar 23, 2019 2:05 pm

Just to test tracking and run a box test without firing a shot, the test scope need not be perfect. Once it is more or less centred, you then never move it during a test. Only the zoom and knob tracking on the scope under test need be changed.
Another thing not fully appreciated - you do not need exquisite optics in the test scope to detect POI movements. Testing for optical clarity and resolution is another matter.

If you are not attempting impact tests, you may use two cheap Chinese Pic Rails available for peanuts. Usually under $10 each. Do not need a ramp angle on the Picatinny rails.

A much better Collimator depends a lot on having a far more detailed Graticule designed for the job but a good riflescope with minute ticks can do the job. It is just a lot less friendly to use.

If anyone really wants to build a very good Collimator, I can provide a suitable Graticule. It will not be small and will need some space. Many of the cheaper astronomical telescopes of suitable focal length available for about $50 in conjunction with a a very good graticule is all you need plus a bit of ingenuity and rough engineering. If the Graticule ticks are not exactly the right size for the lens in the scope, you can easily calibrate it to a very high precision.

Peter Smith.

Rich4
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Re: Is my scope Broke ?

#14 Postby Rich4 » Sat Mar 23, 2019 4:43 pm

I assumed you were using the adjustments of the second scope to measure to, would a cheap scope with Mildots do? Objectives together? Do they need to be centred to each other perfectly? Might be perfect for squeezing doubts from my head, Thanks Rich

pjifl
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Re: Is my scope Broke ?

#15 Postby pjifl » Sat Mar 23, 2019 8:47 pm

Rich4 wrote

I assumed you were using the adjustments of the second scope to measure to, would a cheap scope with Mildots do? Objectives together? Do they need to be centred to each other perfectly? Might be perfect for squeezing doubts from my head, Thanks Rich


Yes. Preferably want about 40X but fairly cheap will work. It will be noticeably annoying to use but will still show tracking errors.
I would very much suggest a 1 minute graticule scale as much better.
Centre the testing scope as well as possible. You will probably need a second person to click its knobs while another watches through the scope under test. Then wind the suspect scope so its graticule centres on a mark in the test scope. Then do a box test with the scope under test watching for even movement and return to the same spot. One can tell if the test scope is close to being set centred by gently turning the scope within loosened rings. Probably do this at reduced power but turn up for final comparison.

A dedicated Collimator made even from a cheap astronomical telecope lens and suitable Graticule is much better to use. One I made and gave away was from a fairly cheap Astronomical scope someone resurrected from the dump.

Peter Smith.


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