I recently re-mounted my US optics MR-10 onto a Remington 700 using ARMS #22 mounts. I couldn't find much info concerning torque specs on the ARMS or the USO website but after some researching I felt confident that 15 inch lbs seemed like a median value to start with. I did not lap the rings, so I realize this may be part of the problem. Anyways I leveled the optic and began to tighten the screws in an X pattern until I reached 15 in/lbs. I went to adjust parallax and the knob would move but it was VERY tight. I immediately loosened the rings, lowered the torque to 12 in/lbs and proceeded to re tighten. The parallax knob moves smoothly now and everything SEEMS fine but as a newby to precision optics I cant shake the feeling that I warped the scope body or did damage in some way. The optical clarity is still fine, parallax adjustment and focus both still work. Even if I remove the scope for visual inspection, I am worried that maybe I jacked up the internals or something. What are some signs I should look for, or function checks I could perform in order to confirm the soundness of the optic? or am I over reacting? Any advice is appreciated
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Rifle Scopes Did I damage my scope?
- Thread starter DanUSMC
- Start date
I think USO warps them for you prior to shipping. I wore out two FedEx trucks and one plane shipping my USO’s back for repair. Never got to the point of getting one to the range.
On the positive side Becky was nice.
On the positive side Becky was nice.
go shoot it and/or do a tracking test. that's what would I would do. if all passes, then I would say you are GTG.
Call USO and run it by them, they will give you good insight on how to test for damage. Are you mounting to a rail? If not, get a good one, mount and bed if needed. You'd might be surprised at how much a 700 will warp a rail if it's not bedded.
I think your scope is OK...USO's have been through worse.
Thank you for the replies everyone. For some reason this is reminiscent of an STD conscience check... Anyways the nice lady at US optics said that I most likely did not damage the scope, but that If I wanted to test it I should run the elevation/wind knobs all the way up and then back down and check for a shift in zero. Ill give it a whirl
I bet your fine.
Recently mounted a different brand scope and what I wanted for eye relief apparently had a ring interfering with the zoom adjustment sleeve when torqued to to 12-15 inch pounds.
Loosened caps, moved scope slightly, tightened back up smooth as butter.
Turns your stomach and makes you feel like shit but if you buy good gear, like you did, it can take some abuse.
Recently mounted a different brand scope and what I wanted for eye relief apparently had a ring interfering with the zoom adjustment sleeve when torqued to to 12-15 inch pounds.
Loosened caps, moved scope slightly, tightened back up smooth as butter.
Turns your stomach and makes you feel like shit but if you buy good gear, like you did, it can take some abuse.
I had a similar issue with a NF scope in a Spuhr mount. The directions on the Spuhr mount said 15 to 25 in-lbs on the cap screws, so I thought I'd use 25 in-lbs to make sure that my 18 pound 6.5 creedmoor didn't rock the scope out of alignment with it's incredibly abusive recoil. With the cap rings clamped down that tight the parallax adjustment had some disconcerting resistance and what felt like backlash in the system!!! I called NightForce immediately, because they had obviously sold me a lemon. They suggested that I don't tighten the rings quite that much and that I can send it in for a check-up. I sent it in. They said it looks great. When I got it back I mounted it in the same Spuhr mount, and I tightened the cap rings down to 15 in-lbs. The parallax works great now. I didn't bother testing the higher torque setting though. I'm just not that curious, I guess.
I dont even go to 15 inch pounds anymore after having a screw twist a way just as I eased it up to the 15IP mark.
12-14 feels fine to me.
Make sure the screws and recess are cleaned with acetone for a nice dry fit.
If you apply loctite let it dry on the screw before using it to secure the cap.
12-14 feels fine to me.
Make sure the screws and recess are cleaned with acetone for a nice dry fit.
If you apply loctite let it dry on the screw before using it to secure the cap.
If you're using a dry cap surface and a dry screw head don't you get a lower compression force than expected for the same torque? Maybe it doesn't matter...
Probably,
If you lube it do you get a higher compression on the screw and bind up your scope or worse snap a screw?
edit/add - Ive seen specs call for lubed or unlubed fasteners on other things.
Never have seen anything in regards to scope cap fasteners.
When I asked someone very familiar with this type of stuff (major manufacturer) he said he he snugs them than goes a 1/4 turn.
Hows that for spec?
I wasn't suggesting it would damage anything; I just thought it may give you a lower torque than you were expecting.
I took your question as you posted it, no malice, no second guessing, just a question.
The answer it may.
The reverse side of the coin though is doing other wise may over torque them.
Truth be told if they are snug and your not shooting a .50 cal Id rather take 11 IP and holding vs 18IP and binding or broken.
On MOST of mine, I go 15 inch lbs. I have never had one slip, turn, etc. the exception is on ARC and they tell you to go MUCH tighter than I normally would. I go, per their specs, on my ARC mount. That’s the only mount I go that tight on.
To the OP: I can’t imagine that a USO could be hurt at 15 in lbs. USO May or may not be everyone’s favorite, but I REALLY think they can take much more than 15 in lads to mess them up internally.
As suggested: set it up, level it, etc. Then shoot it. Shoot a tall target test, and a box test. That’s the only way you’ll know 100%. If it passes your requirements on both, you have peace of mind, and you’re set. If not, in it goes.
I don’t think you have anything to worry about.
To the OP: I can’t imagine that a USO could be hurt at 15 in lbs. USO May or may not be everyone’s favorite, but I REALLY think they can take much more than 15 in lads to mess them up internally.
As suggested: set it up, level it, etc. Then shoot it. Shoot a tall target test, and a box test. That’s the only way you’ll know 100%. If it passes your requirements on both, you have peace of mind, and you’re set. If not, in it goes.
I don’t think you have anything to worry about.
I'm surprised to hear accounts of torque settings as low as 15in lbs interfering with function too. I suspect it was due to the rings not being lapped and the tolerances of the Remington receiver being, well, Remington.
The other day, the recoil of 338 LM dislodged my Tenebraex ARD from its mount that threads into the NF ATACR. I can't help but think that if I only torqued to 15in lbs I'd have movement, even in the Spuhr.
The other day, the recoil of 338 LM dislodged my Tenebraex ARD from its mount that threads into the NF ATACR. I can't help but think that if I only torqued to 15in lbs I'd have movement, even in the Spuhr.
Yea when I asked for a ballpark figure, USO told me over the phone that they recommend 10-15 ft/lbs of torque. I think I need to lap my rings, I've read some anecdotes about ARMS mounts needing quite a bit of material removed, maybe that is exacerbating the issue.
Dan,
You could be correct. Well worth checking out. I have had great experience with ARMS rings on my Mk 12 projects. I have had bad experience with USO scopes so that would be my chief area of concern. Think about it, did you ever hear of a S&B having an issue like that? NF? I don't recall it ever being mentioned. I use those scopes a lot, own dozens and have for 20+ years. I have zero experience shooting USO. None ever made it to range. They quit when I mounted them or before. No kidding. 3 scopes, countless trips to SoCal. One USO gave up on and wanted to make me a new one as it could not be fixed. Might just have been bad luck. I really liked the features. That is why I kept trying.
Good luck with your project.
RTH
You could be correct. Well worth checking out. I have had great experience with ARMS rings on my Mk 12 projects. I have had bad experience with USO scopes so that would be my chief area of concern. Think about it, did you ever hear of a S&B having an issue like that? NF? I don't recall it ever being mentioned. I use those scopes a lot, own dozens and have for 20+ years. I have zero experience shooting USO. None ever made it to range. They quit when I mounted them or before. No kidding. 3 scopes, countless trips to SoCal. One USO gave up on and wanted to make me a new one as it could not be fixed. Might just have been bad luck. I really liked the features. That is why I kept trying.
Good luck with your project.
RTH
Wow hard to believe people having mechanical issues when torquing ring cap screws to 15 in-lbs! Seekins recommends 20 in-lbs for their scope cap screws and I never had any issues with a few different scopes. Now I am using ARC rings that are torqued to 55 in-lbs (but just 1 screw per ring).
We can determine the clamping force of a single ring on the scope tube by summing the tension in each of the screws that holds the ring cap against the scope tube. Let's use the Seekins recommended 20 in-lbs of torque and assume 4 screws per cap. Let's assume the use of some Molykote P-37 thread lubricant so the coefficient of friction of the screw threads can be approximated as 0.15. I believe the ring cap screws are #8-32 which have a nominal diameter of 0.164".
The general relation between torque and tension is given as Torque (T, in-lbf) = Tension (F, lbf) * Screw Dia (d, in) * Thread Coeff. (K, unitless).
To solve for the tension in each screw, the equation is re-written: F = T / (d * K)
Plugging in the variables, and solving for F -----> F = 813 lbf
Therefor with 4 screws, the total clamping force of a single scope ring cap on the tube body is approximately 4 * 813 lbf = 3252 lbf
This seems like a lot, but when we are talking about single piece scope tubes that I believe are usually constructed of 7075-T6 aluminum, it really isn't much at all.
We can now apply this clamping load over the "clamping area" of the scope ring to determine the stress it exerts on the scope body. I will make some more assumptions here to make the math easier. I will assume a ring width or thickness of 1" and I will assume the top and bottom halves of the rings perfectly make contact with the entire circumference of a 34mm scope body.
The area is determined by calculated the surface area of a 34mm diameter cylinder with a length of 1". The radius (r) is equal to 17mm or .67 in, and the length (h) is 1"
Area = 2 * pi * r * h = 4.2 in^2
The stress felt by the scope body is just the total clamping force divided by the area, or 3252 lbf / 4.2 in^2 = 774 psi
Obviously some assumptions were made to make this calculation simple, but you can see that by tightening 4 screws on a ring clamp to 20 in-lbs, the scope body will see somewhere on the order of ~775 psi, which is almost nothing given its construction.
Per the link below, 7075-T6 aluminum has an ultimate tensile strength of over 80,000 psi and a yield strength over 70,000 psi. Also note that these values are for tensile stress, and the stress that I calculated here is more of a compressive (or bearing) stress, which typical materials like this tend to handle better.
http://asm.matweb.com/search/SpecificMaterial.asp?bassnum=ma7075t6
Obviously if you have some junk-ass rings and they are "point-loading" your scope tube, the stress experienced by the tube could spike significantly, but even if the actual stress exerted on the scope tube is double or triple what I have calculated, it is still next to nothing for a quality scope tube. Hope this helps shed some light on scope cap torque vs tension and how it applies to a scope tube.
We can determine the clamping force of a single ring on the scope tube by summing the tension in each of the screws that holds the ring cap against the scope tube. Let's use the Seekins recommended 20 in-lbs of torque and assume 4 screws per cap. Let's assume the use of some Molykote P-37 thread lubricant so the coefficient of friction of the screw threads can be approximated as 0.15. I believe the ring cap screws are #8-32 which have a nominal diameter of 0.164".
The general relation between torque and tension is given as Torque (T, in-lbf) = Tension (F, lbf) * Screw Dia (d, in) * Thread Coeff. (K, unitless).
To solve for the tension in each screw, the equation is re-written: F = T / (d * K)
Plugging in the variables, and solving for F -----> F = 813 lbf
Therefor with 4 screws, the total clamping force of a single scope ring cap on the tube body is approximately 4 * 813 lbf = 3252 lbf
This seems like a lot, but when we are talking about single piece scope tubes that I believe are usually constructed of 7075-T6 aluminum, it really isn't much at all.
We can now apply this clamping load over the "clamping area" of the scope ring to determine the stress it exerts on the scope body. I will make some more assumptions here to make the math easier. I will assume a ring width or thickness of 1" and I will assume the top and bottom halves of the rings perfectly make contact with the entire circumference of a 34mm scope body.
The area is determined by calculated the surface area of a 34mm diameter cylinder with a length of 1". The radius (r) is equal to 17mm or .67 in, and the length (h) is 1"
Area = 2 * pi * r * h = 4.2 in^2
The stress felt by the scope body is just the total clamping force divided by the area, or 3252 lbf / 4.2 in^2 = 774 psi
Obviously some assumptions were made to make this calculation simple, but you can see that by tightening 4 screws on a ring clamp to 20 in-lbs, the scope body will see somewhere on the order of ~775 psi, which is almost nothing given its construction.
Per the link below, 7075-T6 aluminum has an ultimate tensile strength of over 80,000 psi and a yield strength over 70,000 psi. Also note that these values are for tensile stress, and the stress that I calculated here is more of a compressive (or bearing) stress, which typical materials like this tend to handle better.
http://asm.matweb.com/search/SpecificMaterial.asp?bassnum=ma7075t6
Obviously if you have some junk-ass rings and they are "point-loading" your scope tube, the stress experienced by the tube could spike significantly, but even if the actual stress exerted on the scope tube is double or triple what I have calculated, it is still next to nothing for a quality scope tube. Hope this helps shed some light on scope cap torque vs tension and how it applies to a scope tube.
Yea I can hardly read good, so all that math does hurt the insides of my head... I am curious about what some of you mentioned concerning the reciever being warped I had never heard of this. The badger rail is supposed to be pretty good however so I'm surprised it would be so easy to bend
I am looking into bedding my rail for sure now. Thank you everyone, 2 days as an official member and I'm already having me some learnin'
Dont bother bedding the rings, just the rail. Scopes end up getting taken on and off a bunch. Bedding them makes that a pain in the ass. Rails generally stay with the rifle and dont get shifted forward or backwards or on other rifles etc like rings do.
TLDR
Or.... just tighten it with the small end of an Allen wrench as a handle to “medium” tight.... and go shoot....
I swear some guys pants get tight when talking about scope rings and inch pounds.....
Lol didn't know I could catch flak here for actually posting something informative and factual. 
Sorry for cluttering up this thread guys, I thought some might find it interesting to understand how simple fastener torque applies load to your scope tube through the rings. I will let you guys get back to figuring out how to install rings without destroying your scopes.
Sorry for cluttering up this thread guys, I thought some might find it interesting to understand how simple fastener torque applies load to your scope tube through the rings. I will let you guys get back to figuring out how to install rings without destroying your scopes.
That is common for many fasteners. Many use torque turn over a set torque, as all threads are not equal. Many people will lub threads, an many will not, some mfg require lube some say dry. Then you have the torque method of fastener stretch.
I found it interesting. So thank you. This forum used be to filled with people who were knowledgeable and actually shared intelligent and helpful information instead of just giving "answers" that are mostly opinions. I rarely come back anymore because many of those people no longer post and hence the great conversations about reticles, subtensions, torsional loads, muzzle velocity and cool stuff like that are things of the past.Lol didn't know I could catch flak here for actually posting something informative and factual.
Sorry for cluttering up this thread guys, I thought some might find it interesting to understand how simple fastener torque applies load to your scope tube through the rings. I will let you guys get back to figuring out how to install rings without destroying your scopes.
When a 18 lb 6.5 Creedmoor is said to have "abusive recoil" when if you do the math it really has 6.5 ftlbs of recoil force which is less than a .308 shooting a 150 grain bullet I have to say I really miss the old days of conversations and instructional and informative sharing of information. Thanks so much for the education- you are never to old to learn.
Lol didn't know I could catch flak here for actually posting something informative and factual.
Sorry for cluttering up this thread guys, I thought some might find it interesting to understand how simple fastener torque applies load to your scope tube through the rings. I will let you guys get back to figuring out how to install rings without destroying your scopes.
I liked your post but a lot of it made me dizzy.
I have no doubt you are correct about the force applied to the tube and that makes me kind of wonder about what I experienced with my Leupold.
Its not an expensive scope by any means, just a standard Redifield 1 inch tube meant to replicate a scope the USMC used in Vietnam....
As you see it mounted in this picture the magnification adjustment ring works fine. When I first mounted it I had the scope forward maybe so the ring was .25 inch or less from the zoom ring and the scope was binding up. That was at 12-14 inch pounds using a Seekonk torsion beam.
Im reminded of the problems the Premier scopes had with their parallax adjustments due to ring placement and by no means are those crappy scopes. On a few scopes I think they had to retrofit a repair because it was a design issue.
I guess there is science and than there is crappy design.
@pmclaine one thing I did not go into with my post was the resulting deflection of the scope tube under load/pressure. Depending on the specific material and geometry of the scope tube, minor deflection would occur from the pressure exerted by the rings.
My only guess is that when your mounting ring was very close to the magnification ring it must have caused enough deflection in the scope tube or to the internal components to cause them to bind up.
My only guess is that when your mounting ring was very close to the magnification ring it must have caused enough deflection in the scope tube or to the internal components to cause them to bind up.
My sarcasm detector says Malware was being facetious when he spoke of the "incredibly abusive recoil" of his pig of a 6.5CM.
Id be surprised if most of us here when we see a spec that gives a range dont "see" the range and think only the high number is the correct number to torque to.
Less Type A people see a range and go for the middle of the range.
Type B people use the low number, whoa is me.
Id be surprised if most of us here when we see a spec that gives a range dont "see" the range and think only the high number is the correct number to torque to.
Less Type A people see a range and go for the middle of the range.
Type B people use the low number, whoa is me.
So following the trend of this thread, I have ARC rings sitting here awaiting my optic in the mail. I've read reports that their torque values are too high, or is the 55in lbs legit and I shouldn't be worried about it?
OP if this is hijacking your thread, just say so and I'll delete it.
OP if this is hijacking your thread, just say so and I'll delete it.
Arcs recommendation of 55 is just fine. I still use 45 though but have never had an issue. Its 55 on one fastener, others are 15 on 4 fasteners 15x4=60
Dont be afraid to do exactly what the manufacturer says to.
Yes, follow ARC's instructions and you will be good to go. ARC M10 rings are amazing and I would probably never go back to another type of ring again. The simplicity of having only 2 screws to torque per ring is fantastic for removing and mounting scopes quickly and easily. Plus the design is elegant and aesthetically pleasing IMO.
Modern quality rings (Seekins, ARC, Spuhr, etc.) do not require lapping when mounted on a straight and flat rail. If the rail is not straight and flat, the scope mount bores in the aforementioned quality rings that are mounted on it are not concentric (on the same centerline) which is just as bad as using shitty rings on a good or bad rail.
It's pretty easy to bed a rail, but ensure the rail is straight and flat before you bed it or you're not really fixing anything by bedding it.
Ring screw torques of 15 to 25 inch/lbs. are DRY values. I've never used Loctite, always torqued dry ring screws regardless of brand to 20 inch/lbs. (except ARC M10 which require 50 inch/lbs.), never had a screw loosen, and never damaged a scope with quality rings on a straight and flat rail. Lubing ring screw threads with wet Loctite or a lubricant decreases the friction between the male and female threads and between the bottom of the screw head and its mating surface (usually the bottom of a counterbore) so the same rotational torque results in far more clamping force than appropriate and can permanently bend the scope main tube.
It's pretty easy to bed a rail, but ensure the rail is straight and flat before you bed it or you're not really fixing anything by bedding it.
Ring screw torques of 15 to 25 inch/lbs. are DRY values. I've never used Loctite, always torqued dry ring screws regardless of brand to 20 inch/lbs. (except ARC M10 which require 50 inch/lbs.), never had a screw loosen, and never damaged a scope with quality rings on a straight and flat rail. Lubing ring screw threads with wet Loctite or a lubricant decreases the friction between the male and female threads and between the bottom of the screw head and its mating surface (usually the bottom of a counterbore) so the same rotational torque results in far more clamping force than appropriate and can permanently bend the scope main tube.
Thanks everyone. This is my first higher end optic, so I just want to make sure I'm doing my part to take care of it.
