What are the signs of erector failure in a scope?

DNADave

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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. 🤔
Yep, 100yds. That's what is eating me. I would have expected more than 1 out of the last 8 rounds to hit paper. somewhere, even if I was the culprit. Especially with that much real estate to work with.
 

DNADave

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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.
I do not know the exact round count on this rifle as I am the second owner. It has been "well loved" by its previous owner and me. On good days, I can do well enough to do half MOA four shot groups and on great days, around 1/3 MOA. Sunday was an OK day and things weren't bad until the end. I would not expect a binary failure, but rather a slow drift of worsening performance if it was the barrel.

The gun is old enough that I do monitor for barrel wear, though.
 

DNADave

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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.
True, but it was all I could do until this weekend. There are two ranges near me and one is only allowing members (and I am not a member) and the other (the one I went to) is only open Friday through Sunday. So, I'll have to wait until this weekend to try anything under real world conditions.

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.
These last two seating depths were becoming compressed loads. It's a big case, but it's also a lot of powder with a long bullet. For the last depth, that would be a lot of vertical travel for a 0.040" change in depth.

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.
I do not use a rear bag when shooting. The butt of the rifle is only supported by the crease of my shoulder and a consistent backward pressure. I know I can get more consistent with a rear bag, but I don't hunt with one and want to practice (as best as the ranges I go to will allow) how I will shoot when hunting. I do try to be as consistent with my set up such as positioning, cheek weld, pressure with my shooting hand, as possible and I generally do well, but not as consistent as I would be with a rear support such as a bag.

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.
This may be what it was. It was in the upper 80s F here (which is plenty warm for the PNW) and at the point where things started to go awry I had already shot over 50 rounds of two, unbraked, high recoil rifles that each weigh around 9#.

The only thing that makes we question this is that only 1 of these last 8 rounds made it on paper. I would have expected to see a mess of holes rather than a blank. Especially on that last target given most right handed flinches land up and to the right. There was a lot of open real estate on that target in that vicinity for a round to land.

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.
In the upper two targets, both of the flyers I knew were bad once I pulled the trigger. This is something mental I'm working on. I'll get three really good shots in, clover leafs, and then almost always pull the last shot in a group of four. This is me and something I'm working on.

For the last two targets I shot at, the first round felt decent. Certainly not that high. I took some time to calm myself down and really focus for the next shot. Make sure that I was in a good position, my natural point of aim settled on the bulls eye after every breath, and really focused on that shot. Complete miss. For the next six rounds, I tried to do the same, but worry was starting to set in and I can't say that I was as successful at centering myself as I was on that round just after the high shot. Either way, I would have expected to see something on the paper at that distance.

Before I swap scopes, I'll head back out this weekend with a known load and check things again. It may very well be me, I just have a hard time seeing things go that far off the rails that quickly if it is.

I really appreciate your help and advice. From what you have told us about yourself, you have a lot of experience you can impart and I appreciate you took the time to respond.
 

DNADave

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The "NUT" behind the trigger remains the biggest factor.
Oh, I'm definitely a nut. Been diagnosed by my wife multiple times. :)

Dave, what I am saying is that you might have answered your own question/doubt ...
That's well within reason. I just would not have expected those last two targets to be that bad. At least more than 1 round on paper.

Good luck! You got this.
Thanks! Much appreciated.

If I make it back to MT sometime, we should go shooting together.

Dave
 

FEENIX

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Oh, I'm definitely a nut. Been diagnosed by my wife multiple times. :)



That's well within reason. I just would not have expected those last two targets to be that bad. At least more than 1 round on paper.



Thanks! Much appreciated.

If I make it back to MT sometime, we should go shooting together.

Dave
Dave,

L ;)L! Sounds good. Cheers!

Ed
 

DNADave

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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.
Both of the rifles I shot this past Sunday are similar. Both are factory Weatherby Mark Vs with the stocks replaced with B&C stocks I cleared the barrel channel out to float the barrel. Neither have brakes and both are around 9#.

I probably should have called it a day earlier, too, but range time right now is hard to come by.
 

Bravo 4

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Dave I totally understand the desire to practice as you hunt, I feel not enough shooters do that. However you are not practicing, you are testing equipment and need to give it every opportunity to show its potential. Not being rude brother, but if I hunt mostly over a tripod in a sitting position I’m not going to do load development like that. I will do load testing in a control environment (ex: front and rear rear) and then shoot it over the tripod.
Good luck!
 

DNADave

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Dave I totally understand the desire to practice as you hunt, I feel not enough shooters do that. However you are not practicing, you are testing equipment and need to give it every opportunity to show its potential. Not being rude brother, but if I hunt mostly over a tripod in a sitting position I’m not going to do load development like that. I will do load testing in a control environment (ex: front and rear rear) and then shoot it over the tripod.
Good luck!
No offense taken and I do appreciate your advice. I feel I'd need to practice quite a bit with a rear external support before feeling I was shooting consistent enough with that set up as it would be out of the norm for me. Working out the mechanics from just the bits I've read here and in books would take some time.

I was planning on doing one of the long range schools this Summer, but as we all know about our Summer plans this year...
 

David Emerson

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Yes I would say you junked your scope. I have a 416 weatherby on an enfield that weighs 10 pounds scoped and loaded. 1 1/2 to 5 leupold vari x 3. It was shooting about an inch and then went to pot. I took the scope off and it jingled!! lol
 

Quintus

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If you have shot 1/2 minute groups with those rifles it would say the rifle and shooter have the ability, even fatigued to at least stay on paper. I had a...wait for it...erector failure on a 300Wby with a then new model Nikon Monarch (Phillippines Production) and a very old Leupold Vari-x II on a 30-30 single shot H&R. Similar in that the POI shift was enormous. I shot a bigger target and could see what was happening, but it looked like I was shooting a mod choke. Nikon verified and sent a new scope and Leupold sent me the old tube with everything else new. Anxious to see how the next session goes.
 

DNADave

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@Quintus , same here. I should be able to get back out on Sunday. Not hitting paper at all is what had me thinking something might be wrong. @Bravo 4 gave be some tips and I'll try those this Sunday, as well.

I'm not perfect, but I would have expected some more holes somewhere on the paper if it was me (which it still very well could be).
 
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