Rifle Scopes For the experts - scope tracking issue or something else?

[lte82]

I loaded up 10 rounds of some super secret 338 lapua loads a couple of nights ago, and got to shoot them this morning at the 200yd range off my bipod. Load seems to be good but my scope had some seemingly funny tracking...

I just remounted my scope so I had to do a sighter to start off.

Shot 1: 4" high 4" right

Adjusted 8 clicks down and 8 clicks left.

Group 1: 1.2" group (.6 moa), 2" low and 1.5" left (way more poi change than I dialed in)

Adjusted 4 clicks up and 3 clicks right.

Group 2: .5" (.25 moa) group, perfect elev but still 1" left ( elev poi change was fine but my .75 moa adjustment right only came up with a .25 moa on paper)

Adjusted 2 clicks right

Group 3: .9" group (.45 moa), 1" right and 1" low (.5 moa adjustment right turned into a .5 moa elev drop and a 1 moa shift right)

What would cause this? The reticle obviously doesnt shift between shots, and my groups are tight by my standards. It just my POI change when moving the knobs doesnt match down range.

This is a NF nxs 5.5-22x56 mounted in NF rings on an egw 20 moa base. All clicks should be 1/4 moa.

 

[Enough Said]

I'm no expert, so please don't think that by responding to this post I consider myself an expert.
You need to perform a tracking test, either by shooting at a target suitable for a box test, or by gauging your scope's tracking mechanics with the use of a bore laser.

 

[KUSA]

remember it's only a 1/4 moa at 100 yards, at 200 it's 1/2 moa per click,

MOA is the same at 100 or 200 or a even a mile.

Sent from my Galaxy S3 using Tapatalk 2.

 

[BCP]

I loaded up 10 rounds of some super secret 338 lapua loads a couple of nights ago, and got to shoot them this morning at the 200yd range off my bipod. Load seems to be good but my scope had some seemingly funny tracking...

I just remounted my scope so I had to do a sighter to start off.

Shot 1: 4" high 4" right

Adjusted 8 clicks down and 8 clicks left.

Group 1: 1.2" group (.6 moa), 2" low and 1.5" left (way more poi change than I dialed in)

Adjusted 4 clicks up and 3 clicks right.

Group 2: .5" (.25 moa) group, perfect elev but still 1" left ( elev poi change was fine but my .75 moa adjustment right only came up with a .25 moa on paper)

Adjusted 2 clicks right

Group 3: .9" group (.45 moa), 1" right and 1" low (.5 moa adjustment right turned into a .5 moa elev drop and a 1 moa shift right)

What would cause this? The reticle obviously doesnt shift between shots, and my groups are tight by my standards. It just my POI change when moving the knobs doesnt match down range.

This is a NF nxs 5.5-22x56 mounted in NF rings on an egw 20 moa base. All clicks should be 1/4 moa.

You can check your base, rings, look for parallax problems but I bet it will end up being the scope. Same thing happened to me with a super sniper the adjustments didn't jive with what I saw on target, sometimes 10 clicks would be half a mil and then two clicks would be an entire mil.

 

[dcjs]

You simply cannot establish a POI with so few rounds with the accuracy people expect. I know people try to do it all the time, but 3 shot groups just don't cut it. You may get lucky, but you may just as well be further off than you would expect. Questioning your scope's tracking because the center of a 3 shot group moved a couple clicks too far after a single (!) sighter is utterly pointless, and 3-shot-groups in general are almost worthless if you look at the statistics.

Generally speaking, it is much better to test the tracking by putting the rifle into a solid rest and observing the reticle moving on target while dialing the knobs.

 

[Opticsspecialist]

MOA is the same at 100 or 200 or a even a mile.

Sent from my Galaxy S3 using Tapatalk 2.

my wording must have been wrong, but the value changes, each click is a quarter moa, it's .26 moa at 100 yards, it doubles every 100 yards, so at 200 it's .52

baby was teething last night i'm tired sorry for any confusion

 

[lte82]

I agree my cold bore sighter is statistically insignificant, and my 1/2 moa 3 shot groups arent as good as 5-10 shot groups, but it still shows something is going on.

Ill try tracking using a laser or put it on a lead sled and try to watch the reticle on a sight in paper that has the 1" grid.

 

[Rthur]

I would suggest a tracking test. This is how we do them. put 2 targets at the bottom of a 4 foot target board. Use one to check your zero. Above the other place targets every 5 moa. Repeat this until you have at least 7 targets above. I would use a level to place the targets and the target board. Use the non zero target as an aiming point after dialing up 5moa, shoot 3. Dial up 5 more moa repeat. After you have completed the tracking test you will have your answer. I would have had you shoot 5 but the 338 is pricey to shoot.

good luck
R

 

[melloyello]

Did you have your focus set properly for the distance you were shooting?

 

[CoryT]

OS, the click value does NOT change. If the adjustments are 1/4 MOA, they are ALWAYS 1/4 MOA, range has no effect. What you are trying to say is that the linear value of the adjustment varies with the range, .25 MOA moves the strike about .262" at a range of 100 yards and about .785" at 300 yards.

As for the OP, I'm not sure that anything is wrong at all, as we simply do not have enough shots with any given sight setting to know anything at all. Not that a box test and calibration is not a good idea, but not because of these 10 shots.

 

[CoryT]

OS, the click value does NOT change. If the adjustments are 1/4 MOA, they are ALWAYS 1/4 MOA, range has no effect. What you are trying to say is that the linear value of the adjustment varies with the range, .25 MOA moves the strike about .262" at a range of 100 yards and about .785" at 300 yards.

As for the OP, I'm not sure that anything is wrong at all, as we simply do not have enough shots with any given sight setting to know anything at all. Not that a box test and calibration is not a good idea, but not because of these 10 shots.

 

[grayghost]

Not trying to insult the op but it could be the rifle does not like his secret load.

 

[lte82]

One thing I just thought about... If I need to dial up 4 clicks, should I just dial up the 4 clicks, or should I go say 5 clicks up, and then 1 click back down? I know I've always done that with cheap hunting scopes (it's what I was taught to do as a kid), but I figured on an expensive piece of glass I would just go 4 clicks.

Just a thought...

 

[sniperdude]

maybe your scope is saying for you to share that secret

but what I would do is use maybe factory ammo , or if your load is a proven one, take as much of the shooter out of it as possible , shoot from a rest and try some tracking tests

 

[SomeOtherGuy]

At $3-6 per shot I would be examining the tracking really closely before any more shooting. I would set up two yardsticks at 100 yards, one vertical and one horizontal, clamp the rifle in a rest (or improvise something if you need to) and crank the knobs back and forth 10 ways from Sunday checking for consistent tracking. With a Nightforce NXS I would expect perfect tracking, but anything can break or be defective, so I would give this a try first. It will tell you if there's a problem internal to the scope. If not, you can look at the remaining possibilities - mounting setup, rifle accuracy, and shooter accuracy.

 

[lte82]

Lapua brass with .003 neck tension
300gr Scenar
92.2gr RL33
.020 off the lands
FGMM 215M primers

Shoots in the 2600 FPS range. Averaging .5 moa. I've been able to get some good groups with 94gr RL33 but the 92ish gr node is much more consistent.

I have been trying to find a load for the 300gr SMKs because they are cheaper but I haven't been able to replicate the accuracy of the scenars.

 

[lte82]

Did a 10 moa x 10 moa box test using a laser on my 260 rem on the way home from work (had it in my car trunk). Apparently these cheap made in china millet 4-16x50s track damn well and even return to zero. Who would gave guessed.

Time to try the nightforce...

 

[lte82]

Did a lot of tracking tests a couple of days ago (with a laser and on a 1x1 grid), and the scope tracked extremely well. It sucks when your gear doesn't work, but it's even worse when you end up being the cause of the issue... Time to go shoot some more!