What are the signs of erector failure in a scope?

DNADave

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Was out shooting three different seating depth sets in my .300 Wby (2X) and .340 Wby (1X). Finished the .300 Wby with no issues and part way through the set for my .340 Wby I started having problems. Groups were moving in the right direction going from long to short with the first two depths at or more than MOA at 100yds and the third at around 1/2 MOA for the first three shots. The fourth in that set was high, which could have been me (I had already shot 51 rounds through two heavy, unbraked magnums at this point). Starting the next set of four, the first round was higher than the fourth in the prior set and the next three were off the target. The next set had none on the target.

Prior to those last two sets, I was shooting pretty good and finding a good seating depth for the .300 Wby. Up to that high fourth shot, I was shooting pretty good, so I don't think it was me, but I was getting a bit tired by that point.

So, my question to you all is if you have ever experienced a failure in your scope's erector, what did it look like on target?

My set up during the failure was as follows:

Weatherby Mark V Stainless in B&C stock with barrel floated chambered in .340 Wby Mag
Hornady ELD-X 230gr pushed by 94.1gr RL-25 and Fed-251M primer
Riton RT-S MOD 5 GEN 2 6-24x50 IR FFP 30mm with Riton Rings and Weaver bases
 

26Reload

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The crosshairs didn't break? Shine a lite in from ends of scope looking for cracked wires..
Found this once with 300wby..
Few good shots the off to the side a ways.....
Lot of ammo to figure out the simple problem....
You should be able to see it not moving if you watch while turning at home...
 

BallisticsGuy

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I've seen literally dozens of scopes fail to hold adjustment. Sometimes the turrets stop letting you turn them, sometimes twisting the turrets does not cause a POI shift or the shift is unpredictable, sometimes you think you have it set, then you load one more shot and it's off the paper. If you weren't flinching by the end of the day you're more man than me so i'm going to go with, probbaly not the scope. Maybe mounts, maybe shooter, maybe something else.
 

DNADave

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Sometimes twisting the turrets does not cause a POI shift or the shift is unpredictable.
I'll check that to the best of my ability tonight.

If you weren't flinching by the end of the day you're more man than me so i'm going to go with, probably not the scope.
I use a PAST shoulder pad when I'm going to run that many rounds down the tube in either of these rifles. It makes a huge difference and keeps the flinch away (well, at least most of it).

https://www.amazon.com/dp/B001C5XOJQ/?tag=lrhmag19-20
 
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DNADave

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I placed my rifle in my cleaning vise and aimed at a point marked on the wall down a long hallway. I was able to get the scope to track up and down from my point of aim and clicks were solid and not sloppy.

It must have been me, but I've never had a session go off the rails so bad. The last two sets of four rounds only had one on target and that one was 6 inches high. The last set of four were not on the target despite having a good 14 inches to play with in the upper vertical and about 20 inches of play to the right horizontal.

The target in question is below. The upper left and middle were the last good 4 shot sets (each had one flyer that likely was me). I probably could do better if I had a rear bag, but I typically don't use one. The upper right was the four shot set where I only placed one on the target high. The bottom left had none of the four hit the target. I've had bad days, but I always at least hit paper.
20200728_005322.jpg
 
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Deputy819

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The bottom left had none of the four hit the target.
This happened at 100 yards? If it had been a longer distance I’d say that maybe your cheek-weld to the comb wasn’t consistent, but I don’t think that’s the case here. 🤔
 

Laelkhunter

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How many rounds down the tube?? May be time for a rebarrel?? I had my .340 since 1988, and shot it a bunch. It started doing the same thing. I had it rebarreled by Rich Reilly at Hi Tech Customs in Colo Springs. He works wonders with the .340 Wby. It now shoots sub-moa groups again.
 

Bravo 4

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Having it track in a controlled setting, like putting the rifle in a vise proves that it will only work in a controlled setting. It proves nothing under recoil. I do mount my LR scopes on a fixture and test them before mounting, have found rather expensive big name scopes that have been off by as much as 10% (which is a huge amount) before even “waisting” ammo. I’ve also had scopes that I had to zero every time I took it out, scopes with wandering zero, would sling a round, and on and on. If you think it’s the scope then put a proven scope on that rifle and check, or/and check that scope on a proven rifle. I’ve often found that guys blame the scope when it was something loose in the mounting system.
Other things not scope related:
When you change anything on a load, it changes the load and potential poi. Just adjusting seating depth I wouldn’t expect a huge change though, but you never really know. I do have to ask, are you not supporting the rear of the rifle at all? If not you are going to have issues being consistent, that’s shooter error. Even if you do support the rear, if you’re not consistent with it then that is inducing error. You also mentioned possible shooter fatigue. You have to be honest with yourself, if when you break the shot you don’t know where the poa was (call the shot) or think you pulled it then to me you did something wrong. I would try again, but either with a proven load and/or scope (take both scopes as they are easy to swap) making sure I am giving the rifle every opportunity to perform (or to not) by properly supporting it. Or have someone (again proven) else shoot it. You need to eliminate the possible errors systematically, one by one. Honestly I would be putting myself at the top of that list.
 

FEENIX

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Or have someone (again proven) else shoot it. You need to eliminate the possible errors systematically, one by one. Honestly I would be putting myself at the top of that list.
^^^THIS!^^^. The "NUT" behind the trigger remains the biggest factor.

Was out shooting three different seating depth sets in my .300 Wby (2X) and .340 Wby (1X). Finished the .300 Wby with no issues and part way through the set for my .340 Wby I started having problems. Groups were moving in the right direction going from long to short with the first two depths at or more than MOA at 100yds and the third at around 1/2 MOA for the first three shots. The fourth in that set was high, which could have been me (I had already shot 51 rounds through two heavy, unbraked magnums at this point). Starting the next set of four, the first round was higher than the fourth in the prior set and the next three were off the target. The next set had none on the target.

Prior to those last two sets, I was shooting pretty good and finding a good seating depth for the .300 Wby. Up to that high fourth shot, I was shooting pretty good, so I don't think it was me, but I was getting a bit tired by that point.
This reminds me of shooter at a range in NM a few years ago. I was out shooting my rifle and my sons' rifles one last time before a hunt. Fired 3 shots each and packed them. While waiting for the range to be safe and clear so I can retrieve my targets, I was admiring the shooter's beautiful rifle set-up next to me. However, he seems to have some problem because he keeps shaking his head and adjusting his scope. He asked me if I can shoot his rifle to confirm/validate the problem, obviously, I obliged. 😇 As I take the position and get comfortable, I noticed a couple of empty boxes of factory .30-06 ammo laying around on the ground and another half-empty on the bench. Looking through the scope, he is definitely all over. I squeezed 3 rounds and they were well within 1 MOA at 100 yards. The best advice I can give him that day was to call it a day and come back another day and try again.

Dave, what I am saying is that you might have answered your own question/doubt ...

but I was getting a bit tired by that point.
Good luck! You got this.

Ed
 

swe123

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PAST or not the central nervous system is still taking a beating.
 

Gar Guru

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I shot my Rem 700 factory gun in .300RSAUM 11 times Sunday and I knew it was time to quit for another day. It is a fairly light gun and does not have a brake. I had the best session I have ever had with it out to 700 yards but I was starting to anticipate the recoil so I stopped.
 

Radman

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I've seen literally dozens of scopes fail to hold adjustment. Sometimes the turrets stop letting you turn them, sometimes twisting the turrets does not cause a POI shift or the shift is unpredictable, sometimes you think you have it set, then you load one more shot and it's off the paper.
Total agreement. What really burns me the most is a bad, brand new one, straight out of the box! I've seen more than one brand new scope that was apparently "stuck" & didn't want to adjust at first. I attribute this to long-term storage in a warehouse somewhere (?).
 
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