nightforce dialing

[benny243]

Noticed today my n.x.s isnt dialing windage as it should one click should be 1/2 moa @200 but its actually moving it 2" anyone had this problem?

[justin credible]

Are you sure that you are dialling one click or one moa?

NXs scopes either dial 1/8 or 1/4 moa for one click of the windage, this is the same for any range whether 100,200 and so on.

One click on a 1/4moa Nxs would move the poi 1/4 inch at 100 yds or 1/2 inch at 200 yds.

To achieve a 2" poi change at 200 yds, you would be dialling 4 clicks or 1 moa.

If you are dialling 1 click and your poi has moved 2" at 200yds, then it is likely that the wind has just blown a bit stronger.

[gbal]

It's possible,but unlikely,that you NF is out by a factor of 4 (ie one click giving 2 inches rather than !/2 inch at 200y.

Is Justin's point about wind ....err ..credible (sorry!).

Let's say you were zeroed at 200 y, but 'yesterday' noticed a shot (group?) was 1/2 inch right (you'd need a 5 shot group to have some confidence-1/2 inch at 200 is a pretty small margin...) .So was there a very light wind from the left?,which might explain this 1/2 inch drift to right? If so,you clicked one left to compensate.....but found the bullet ( just one?) went 2 inches (+4 normal clicks) left.

That might be wind increase ,esp if it was very light from left,but after you adjusted was now a bit stronger from the left ....that is clearly possible. As you don't mention cartidge,it's hard to quantify,but just to give some context, a 223 and 308 would drift about 5 and 3 inches respectively at 200y in 10mph,and pro rata less in a gentle puff-so an initial 1/2 inch drift implies a very light wind- under 2 mph.....but an increase to say 6 mph would overcome your corrected 1/2 inch and drift a couple inches more-BUT of course to the right...

SO-to get that 2" apparently odd 'correction' left you imply,the wind would have to either change direction completly,and increase,

OR you were not zeroed at 200 at all,and wind drift of "1/2 inch left" was mistaken-

OR you dialled the wrong way,and the increased wind just added to the mistaken 1/2 inch 'correction"

OR the rifle isn't a moa grouper.No way for us to tell,without more data.

 

Given NF reliability,a scope error x4 is unlikely; an error in dialling and small wind change seem favourite....but we are dealing wih quite small differences and very small samples here (maybe just two shots,as reported....)

Did it repeat,did wind fluctuate ( 2-6 mph isn't a lot,but noticeable with care.Did 3 clicks send bullet 6 inches off...?

 

gbal

[benny243]

Thanks for the replies

I shot the first 5 shot group which was just to the right of the target so turned one click I.e 1/2 m.o.a @200 the next 5shot group landed 2"left if anything the wind which was barely there was from behind and had dropped completely for the second group so i would imagine if anything it would have brought the group the other way, also its visible at 100yds that a click moves an inch

[onehole]

Best you strap the scope down to a well and truly fixed position,,put out a suitably marked card in MOA at 100 yrads and test again.,,,,O

[blackburnbuccaneer]

Thanks for the replies

I shot the first 5 shot group which was just to the right of the target so turned one click I.e 1/2 m.o.a @200 the next 5shot group landed 2"left if anything the wind which was barely there was from behind and had dropped completely for the second group so i would imagine if anything it would have brought the group the other way, also its visible at 100yds that a click moves an inch

 

I think you are slightly misunderstanding how Minutes of Angle work.

I am Assuming the scope clicks are 1/4 MOA? If so 1/4 MOA is 1/4 MOA whether it be at 100 yards or 1000 (it is a constant value it is just what it translates into in inches that increases with distance) so one click at 200 should be roughly 1/2 an inch but it is still 1/4 MOA. Therefor 2" at 200y is the equivalent of 1 MOA or 4 clicks on your scope.

[gbal]

"Curiouser and curiouser", exclaimed Alice (Alice Through The Objective Glass).

 

OK,lets take on board BBB's point- I/4 min click moves POA 1/4 inch at 100 and 1/2 inch at 200 (not 1/4 and 1/2 moa)-I assumed you just made a slip in desribing,and that the actual movement from one click was indeed expected to be 1/2 inch at 200,to bring group central,from 1/2 inch right.

We are ssure it's an moa turret,not a Mil one? (one mil os about 3.4 times one moa-but that woud not really fit anyhow).

So we have first 5 shots impacting at 200y one half inch right,very slight wind from behind.

You think you corrected appropriately by dialing one click L(ie 1/2 inch at 200y Left) and fired the second five shot group ( even less wind) but impact was now 2" left,rather than the expected dead on.

So one click L turret correction resulted in two and a half inches Left on target at 200.

Can we assume group size is small enough to make an inch/two on target really meaningful-ie the group is itself clearly better than 2inches?

AND you have checked at 100y,and i click moves POI an inch.

 

Does begin to sound like overcorrection,as you implied,and by a factor of four (or 3.4!?) IF your wind turret is indeed moa and not Mil. I believe some scopes were not always consistent between turrets...(and reticules)-a recipe for mischief indeed.

 

Any reason the scope might have suddenly gone off so much?

 

Sorry to go back twice,repeat a bit,but without all the data diagnosis is ....speculative! (..in Wonderland)

 

gbal

[srvet]

Sounds like the scope needs a box test running