Most definitive way to determine scope failure

[MThuntr]

Go on amazon, order new one "free returns".... see where i am going with this?

There's a chance of getting a phony

 

[mtmuley]

Just that. What's the absolute most reliable way to pinpoint scope failure as the culprit for accuracy issues? Box test?
I've got a 300wsm on a M70 action, 26" proof sendero barrel. Less than 70 rounds through the rifle. I checked the action screws, base, scope mount, barrel clearance, all good. Bore scope shows nothing remarkable in the barrel, no baffle strikes, the chamber is a little rough, but no problems cycling ammunition or spent cases. Spent brass looks normal, no indications of problems with the brass.
New factory loaded Norma 180 gr ammo , all from the same lot.
Scope is a Leupold VX-6HD, purchased new and only mounted to this rifle. The scope has already been warranty serviced by Leupold once after less than 30 rounds for a completely seperate issue and all the internals passed inspection. New mounts, remount the scope and it's a shit show all over again.
Group one is after I've made rough adjustments just to get it on paper. Looks good and what I'd expect this rifle to shoot, I make my final adjustments and shoot group two. It's off by 3/4 moa for some reason, no big deal, I dial 3/4 left (elevation wasnt touched)and put the rifle on the rack to cool.
Group three has me scratching my head. I shoot six rounds , make the corrections on the windage (not elevation) and let the rifle cool again.
Group four goes from one extreme to the other, I dialed 1/2 moa left , let the rifle cool.
Group 5 is when I called it quits, at this point I'm so frustrated that there is no point in continuing.
I'm open to questions or suggestions about something I may have missed, but I'm leaning towards a defective scope at this point.
First pic is from my session yesterday, second is from Aug 2023 using the same scope and ammo before I sent it in for warranty. I was able to get four rounds before it started spraying the target like a shotgun, that ended up being a mounting issue causing the need for Leupold service.
View attachment 308930
View attachment 308931

Seems you are pretty knowledgeable. Why are you asking for help? mtmuley

 

[mtmuley]

I like this idea, it's the fastest solution and why pay for prime if I'm not going to enjoy the benefits?

Wow. mtmuley

 

[winmag]

I don't think it's a parallax issue, and yes I have a borescope but I doubt I can see the laser past 20 yards in daylight.

I was thinking more the type where you’re looking at a grid through the scope. A $35 Bushnell magnetic bore sighter would work.

 

[perma]

I was thinking more the type where you’re looking at a grid through the scope. A $35 Bushnell magnetic bore sighter would work.
View attachment 308935

I have one of those. They’re really nice.

 

[brockel]

Ahh the old wandering zero leupold. Send it in.

 

[millerkiller77]

Seems you are pretty knowledgeable. Why are you asking for help? mtmuley

Seeking input from other knowledgeable folks that may have had a similar experience and possibly some input on something I may have overlooked. Doesn't hurt to ask.

 

[mtmuley]

Ahh the old wandering zero leupold. Send it in.

Shit. I might break in my barrel without a scope. mtmuley

 

[Fire_9]

What mounts do you have it in and what did you torque them to?

 

[millerkiller77]

What mounts do you have it in and what did you torque them to?

American Rifle Company M-Brace mount torqued to 55 in-lbs , per the manufacturers instructions.

 

[pilsner]

Ahh the old wandering zero leupold. Send it in.

I just got home from the post office sending one in myself. Once the new one gets here it's going up for sale.

 

[Hillbilly delux]

I would try swapping the stock if you have one that will fit it.

 

[Coyote Assassin]

The most definitive way to determine viability of a scope is a scope checker. Most notably the Hood scope checker. The devise mounts 2 scopes side by side, one of which is frozen by glueing the erector tube in place so it can't move. The scope under exam is adjusted to the same point of aim as the frozen scope, and the rifle is fired. If the subject scope is looking at a different point of aim after the shot, it's defective. Google "Hood scope checker" to find images and text on how it works. There's no guessing about the quality of a scope after this test.

 

[millerkiller77]

I would try swapping the stock if you have one that will fit it.

Lol, that's not an option.

 

[Wind Gypsy]

Definitely would get a different proven scope on to check it out.

I've had good luck and no issue using ARC M10 rings torqued to spec but with more robust scopes than the leupy vx line. I thought i had read some conflicting stories about the torque spec on the ARC rings causing problems previously, found this on the hide:

 

[millerkiller77]

Definitely would get a different proven scope on to check it out.

I've had good luck and no issue using ARC M10 rings torqued to spec but with more robust scopes than the leupy vx line. I thought i had read some conflicting stories about the torque spec on the ARC rings causing problems previously, found this on the hide:
View attachment 309007

That's good to know, thank you.

did the owner of ARC tell him he was too stupid to reproduce, or did I read that wrong?

 

[nhenry]

55 in-lbs might be too much for the leupold. I recall an over torquing issue that they have with anything higher than like 30 in-lbs ish

I can’t find the info to back up this info, so take it with a grain of salt.

Edit: Wind Gypsy sent the same sort of info while I was looking/dealing with my kid

 

[Wind Gypsy]

That's good to know, thank you.

did the owner of ARC tell him he was too stupid to reproduce, or did I read that wrong?

No, you read that right. Ted doesn't shy away from offending his customers.

Another post from Ted on a similar thread:

Threads like this are annoying but they do offer an opportunity to set the record straight.

First and most importantly, know the follow:

Attaching a scope to a rifle in a way that can resist the forces of recoil without slippage will deform your scope.

I make that assertion assuming the scope is constructed from aluminum and that it has a smooth, hollow, and cylindrical interface around which we will install a clamp for the purpose of securing the scope to a rifle.

It is not uncommon for a rifle to accelerate at 100, 200, or even 300 g’s during recoil. If your scope weighs about two pounds and the rifle accelerates at 200 g’s, then the rings must clamp tightly enough to impart a friction force of 400 pounds during recoil to prevent slippage. Assuming a coefficient of friction of 0.3 for anodized aluminum against anodized aluminum, we must apply a force to the scope tube of at least 1333 pounds, or 667 pounds per ring. That is a lot force and it will deform the shit out of your scope tube, regardless of how much money you spent on it. Furthermore, it will result in a slight misalignment of the ocular and objective lenses because we can not squeeze the scope in a way that is perfectly axisymmetric.

In short, scope rings, ours and everyone else’s included, seemingly do terrible things to your scope. But, none of that really matters. Years ago, I discussed this matter with an extremely well qualified engineer from Hensoldt and he concluded what reality had already demonstrated a million or more times over. It does not matter. And apart from designing scopes with a dedicated mounting interfaces (which has been done) there is nothing that can be done about this because the solid materials our universe makes available to us for making scopes, rings, and nearly everything else are all elastic.

So, regarding the practicalities of mountings scopes to rifles, do the following.

• Place rings on rail, gently biased forward in the recoil slots and snug the rail clamp screws, just a little bit.
• Place scope in rings and snug the scope clamp screws, just a little bit.
• Rotate scope to align reticle.
• Tighten scope clamp screws.
• Tighten rail clamp screws.
• Go shoot and be happy.

Any wish for perfect alignment during installation is meaningless because once you tighten the screws, your perfect pre-tightened alignment goes right out the window. That’s reality no matter what you read on the internet or what your gunsmith is selling to you or what Tinkerbelle may be whispering in your ear.

All that said, it is worth telling you a little bit about how we make our rings and the material from which they and your rifle’s upper are made. The rail interface and the scope bore for the rings are machined in the same setup, so we are working within the limits of tool deflection and machine repeatability. The scope bore is cut using a polycrystalline diamond edge that essentially never wears out. Pretty amazing but diamond is hard, and aluminum is soft. The rail clamp portion of each ring is certainly flexible and when you tighten the rail clamp screw, you are effectively driving a wedge (the Pic rail of your rifle) into the rail clamp. It is practically impossible to tighten the rail clamp screws so that both rings will deflect in exactly the same way. Moreover, the desire to do such a thing knowing what you now know about the elastic nature of solid materials in this universe is indicative of mental illness. (I’m assuming you’ve read everything that came before that last sentence and I'm trying to keep it lighthearted.) That said, steel rings will undergo less rail clamp deflection than aluminum rings because steel is three times stiffer than aluminum. I don’t mind the flexibility in the aluminum rail clamp because flexible bolted connections are pretty good at staying tight which is a desirable characteristic in a scope ring.

Also, apart from designing the scope clamp portion or our ring in a way that nearly eliminates annoying scope rotation when tightening the scope clamp screw, we make no effort to enhance the customer’s scope mounting experience. It does not get any easier than what we currently offer.

Regarding the straightness of your rifles rail, again, it does not really matter. We and all other ring and one-piece mount manufacturer’s are going to bend your scope after the screws have been tightened, whether you like it or not. But your rifle’s upper is likely made from 7075 aluminum. Good stuff, to be sure, and among its many available tempers are T735XX and T65XX, the latter undergoing a stress relieving operation by stretching. This can be important for some structural parts such as AR uppers because after machining has been completed, we want our parts to be shaped as we designed them. We never really get that, but we get close enough. So your rail isn’t perfectly straight, none of them are, but it is extremely likely that it is more than straight enough.

Opting for an attempt at kindness that conveys truth instead of politeness, on behalf of American Rifle Company and presumptuously all other manufactures in our industry, stop fussing over shit that does not matter. We are all working on producing stuff that we hope will make you happy and offering it to you for a fair price. Just shoot and be happy.

Ted

 

[Wind Gypsy]

55 in-lbs might be too much for the leupold. I recall an over torquing issue that they have with anything higher than like 30 in-lbs ish

I can’t find the info to back up this info, so take it with a grain of salt.

You're probably aware of the difference with torque values on the ARC rings compared to typical scope rings? 30 is pretty light for the ARC rings because it is a single larger diameter screw compared to the typical 4 smaller diameter screws so it needs more torque to get similar clamping force.

 

[nhenry]

You're probably aware of the difference with torque values on the ARC rings compared to typical scope rings? 30 is pretty light for the ARC rings because it is a single larger diameter screw compared to the typical 4 smaller diameter screws so it needs more torque to get similar clamping force.

I was not. Didn’t know about the ARC design. Makes sense though