Scope mount loosening (Read 2426 times)

robtmc

Scope mount loosening
« on: May 16, 2022, 04:46:54 AM »
Posted in General of my shooting session that featured my scope slipping in the mounts.

New to scopes, and figured, how hard can it be to mount one.   Have decent mechanical skillz, but maybe not judgement.  I mistakenly lightly oiled the inside of the rings after lapping and removing the anodizing. 

I suspect that even with proper torquing of the screws, the oil may have squished out and released some of the screw tension.   Had a Torx tool with me and sure enough, at least one screw was not tight.

Suspect that oils should be kept away from scope rings entirely.  How about screw threads to make sure proper torque is set?

Any suggestions from scope users?

drck1000

Re: Scope mount loosening
« Reply #1 on: May 16, 2022, 07:16:11 AM »
For riflescopes, I typically make sure no grease/oil on the screws.  Many come with some light coating (somewhat like loctite) to help ensure no movement.  I don't add blue loctite on the scope rings for my bolt guns.  When cleaning, I will typically check the torque on the rings and base.  Usually when cleaning the first couple times after mounting, and then here and there after that.  I will apply a light coat of oil on the scope base just before mounting (was recommended to me a long time ago).

For the 1-8 I have on my AR, I will check the screws more often as well as put witness marks.  Figure the higher rate of fire making it more prone to working/vibrating loose.  Haven't had one move, but good to have means of quick verification.  I'll typically use blue loctite on most mounting screws on my ARs, except for my1-8 scope though (wasn't recommended by mount manufacturer, so just went with it). 

I've read where some apply rosin where the rings touch the scope body.  Spuhr mounts recommend it for larger calibers, like magnums.  I haven't used it on my .308 or 6.5 cm, but the recoil on those are mild. 

robtmc

Re: Scope mount loosening
« Reply #2 on: May 16, 2022, 09:46:28 AM »
The one piece clamp on the rail was not loosened at all, but it does have recoil lugs.  I have some Kapton tape if this continues to be an issue.   I know to check the torque now and may add some witness paint.

zippz

Re: Scope mount loosening
« Reply #3 on: May 17, 2022, 11:06:08 PM »
Get or borrow a torque screwdriver to apply the right amount of force.  Usually not required, but you could put some loctite if it gets loose again.

robtmc

Re: Scope mount loosening
« Reply #4 on: May 18, 2022, 04:15:12 AM »
Get or borrow a torque screwdriver to apply the right amount of force.  Usually not required, but you could put some loctite if it gets loose again.
Have one, rings were torqued with one, hence the thread about loosening.   DId not bring it to AZ and recheck.  The issue is loosening over time.

Thought, torque and it is good.  Wrong.

Saw a comment elsewhere of a guy that took his Wheeler to the range and checked the mounts of other shooters.  Said many were not at proper torqued levels.

I am left with it being a mistake to put oil between rings and scope.  He film may squeeze out enough to relax the screw tension.
« Last Edit: May 18, 2022, 04:30:08 AM by robtmc »

Flapp_Jackson

Re: Scope mount loosening
« Reply #5 on: May 18, 2022, 10:08:23 AM »
Have one, rings were torqued with one, hence the thread about loosening.   DId not bring it to AZ and recheck.  The issue is loosening over time.

Thought, torque and it is good.  Wrong.

Saw a comment elsewhere of a guy that took his Wheeler to the range and checked the mounts of other shooters.  Said many were not at proper torqued levels.

I am left with it being a mistake to put oil between rings and scope.  He film may squeeze out enough to relax the screw tension.

Is there a reason one would not apply at least some version of loctite?  I don't see most people going through all the trouble of lapping, torquing and leveling a scope just to remove it from the mounts and do it all over again and again. 

If frequent removal and installation is a requirement, then a one-piece removable quick mount would be better so the scope is always leveled and on the same lapped plane with the rings.

When I add a scope to a rifle, that scope stays mounted unless I find a need to swap it out.  That's only happened once as one .22LR cheap-a$$ scope needed to be replaced. 

I know there are some who like to alternate between a scope and iron sights.  Seems like an unproductive exercise in reinstalling the scope after it's already zeroed.
The reasonable man adapts himself to the world;
the unreasonable one persists in trying to adapt the world to himself.
Therefore, all progress depends on the unreasonable man.
-- George Bernard Shaw

drck1000

Re: Scope mount loosening
« Reply #6 on: May 18, 2022, 03:32:17 PM »
I haven't used blue loctite on any of the scopes on my bolt guns.  The screws or nuts have never come loose.

That said, nothing wrong with using blue loctite.  If you do use, be careful when applying wet as that will affect the torque.  There are many folks who have torqued to the "spec'ed" rating, but where the blue loctite acts as a lubricant and throws off the actual torque.  I know of a couple of folks that happened to, but those were cheaper scopes.  So less durable tube could have attributed.  Interesting that scope ring and mount manufacturers vary greatly on their recommendations for loctite.  Similar to feedback you'll see on a couple of the forums geared toward precision rifle, which is about 50/50. 

I applied loctite to the ring screws for my 1-8.  I applied to the screw, then let it sit to dry for a bit and then installed.  That's similar to how I've seen some screws come from the manufacturer with thread locker already applied. 

Another common trick is application of clear nail polish to the top of the screws.  I've never tried it though. 

While my scopes don't move that often, I know many folks who try all sorts of different optics.  As well as upgrade optics here and there.  I am mostly a "set it and forget it" person when it comes to my scopes.  I mostly use Spuhr mounts, so changing from gun to gun is pretty quick. 

robtmc

Re: Scope mount loosening
« Reply #7 on: May 20, 2022, 08:04:13 AM »
GWIW, bought a new Wheeler torque wrench.  For grins, tried coupling them to each other and see if they pop together at the same setting.

My older wrench had a rather vague setting window, the new one is more precise.

Preliminary indication is the old wrench needs a higher indicated torque setting to pop in synch with the new one.

May have been under torqueing things for some time.  Going to think about setting up some sort of junkyard calibration.

Some weights, a lever, how hard could it be?

aaronc5362

Re: Scope mount loosening
« Reply #8 on: May 21, 2022, 06:00:43 AM »
What did you torque the rings at?

Sorry i may have missed it.

Also i use vibratite. Ebay is prob cheapest. But can use nail polish as another stated.

Also if I lap rings. Instead of oil which will leak out I use blue loctite. Or green. Learned this from a water buffalo hunter dude. Even though its not necessary on small caliber rifles... I still do it lol

robtmc

Re: Scope mount loosening
« Reply #9 on: May 21, 2022, 12:44:17 PM »
What did you torque the rings at?
Aero Precision specs were 15-in/lbs.  Base screws stayed tight, just the rings loosened. 
Hence my suspicion the oil squeezed out and relaxed screw tension, as well as promoting slippage.

As mentioned, my ancient Wheeler torque screwdriver seemed to be off on the low side compared to a brand new version.

Just was out in the old circus I call my tool chests.  Many tools older than most posters here I suspect.  Anyway rigged up an old Craftsman beam torque wrench to connect to the original Wheeler.   Sure enough, it is about maybe 20% off on the low side.  Assuming a linear relation, that would make a desired torque of 15 be more like around 12 in/lbs or so.  Torx screw heads on base and rings.

Posted that the rings were lapped, but smeared with a light coat of oil and the newfound slight under torque.  Next trip I will evaluate the grip after retorque with the new Wheeler.   Have some Kapton tape on hand to add if needed.  That worked with spring air rifles that always slipped.

aaronc5362

Re: Scope mount loosening
« Reply #10 on: May 22, 2022, 03:02:16 PM »
Aero Precision specs were 15-in/lbs.  Base screws stayed tight, just the rings loosened. 
Hence my suspicion the oil squeezed out and relaxed screw tension, as well as promoting slippage.

As mentioned, my ancient Wheeler torque screwdriver seemed to be off on the low side compared to a brand new version.

Just was out in the old circus I call my tool chests.  Many tools older than most posters here I suspect.  Anyway rigged up an old Craftsman beam torque wrench to connect to the original Wheeler.   Sure enough, it is about maybe 20% off on the low side.  Assuming a linear relation, that would make a desired torque of 15 be more like around 12 in/lbs or so.  Torx screw heads on base and rings.

Posted that the rings were lapped, but smeared with a light coat of oil and the newfound slight under torque.  Next trip I will evaluate the grip after retorque with the new Wheeler.   Have some Kapton tape on hand to add if needed.  That worked with spring air rifles that always slipped.

Ah I see I see. Is it the cantilever mount where the top is like "hinged" sort of speak?  I don't really mean hinged but it's not screws its like a puzzle piece? Lol

Yea I inhereted some of my grandpas hand tools. Its amazing how they did things back in the day. Idk if they male it anymore but I have a hand crank drill. I never use it though. But I kept it when he passed on cause I think its awesome lol.

I'd also try some purple/ green/ blue loctite instead of oil on the rings. In a year or so, heat will prob dissipate the oil conpletely. But also if your mount is the one I'm thinking of its 6061 aluminum. Trust me it'll never rust ever. I had a mount I altered that was 6061. The part I cut off is still in my garage sink. Bare aluminum. 100s of not 1000 cycles of my washer and everyday I use the faucet to wash my hands and clean my doggy bowls. Not 1 single speck of rust that I can see. Lol

But good luck and let us know!  I also use a wheeler fat wrench. I wonder if mine is out of spec too. But I usually go 3-5 inch lbs higher than recommended. It wont hurt yfs bolts.

robtmc

Re: Scope mount loosening
« Reply #11 on: May 22, 2022, 03:26:18 PM »
Yeah, the Aero rings "hook" together at the top.  Took a good bit og lapping, suspect the loose ring halves are made as an extrusion, so when mated with the large cast base, it is not real close to ideal diameter.
No Matter, I have 1' and 30mm lapping bars.   The 30mm is no more than a 30mm precision bar from McMaster.  Drilled the centre to accept the handle from the 1" kit.

The older Wheeler has a very broad band for an indicator, so you stare at it wondering what do you line up with the numbers?  Top/bottom/middle?
On their scale, that band is a good 5 in/lb wide.  New wrench is a much more narrow band.

Will have the new wrench with me next Arixzona trip, so i can monitor screw tightness.  Will wait on locking compound until I see how that goes.

DocMercy

Re: Scope mount loosening
« Reply #12 on: May 27, 2022, 11:04:04 AM »
I haven't used blue loctite on any of the scopes on my bolt guns.  The screws or nuts have never come loose.
That said, nothing wrong with using blue loctite.  If you do use, be careful when applying wet as that will affect the torque.  There are many folks who have torqued to the "spec'ed" rating, but where the blue loctite acts as a lubricant and throws off the actual torque.  I know of a couple of folks that happened to, but those were cheaper scopes.  So less durable tube could have attributed.  Interesting that scope ring and mount manufacturers vary greatly on their recommendations for loctite.  Similar to feedback you'll see on a couple of the forums geared toward precision rifle, which is about 50/50. 
I applied loctite to the ring screws for my 1-8.  I applied to the screw, then let it sit to dry for a bit and then installed.  That's similar to how I've seen some screws come from the manufacturer with thread locker already applied. 

This is also the advice given by Brownells.

Ostrem suggests using alcohol to degrease threads that do not already have Loctite applied to them.

I own both the digital and analog versions of the Wheeler torque wrenches. When I put a red dot sight on a pistol I did not feel confident in the torque value that was actually applied. This led me to order a few Fix It Stick torque limiters, which range for 10 inch-lbs up to 80 inch-lbs.
https://smile.amazon.com/gp/product/B015S8WWS6
A semi-complete set of limiters costs over $500. This is uber OCD, and may be overkill for some gun owners. However, for a competitive rifle shooter who needs to adjust his scope at the range, it may be appropriate vs. carrying a complete set of tools.

drck1000

Re: Scope mount loosening
« Reply #13 on: May 27, 2022, 11:23:05 AM »
This is also the advice given by Brownells.

Ostrem suggests using alcohol to degrease threads that do not already have Loctite applied to them.

I own both the digital and analog versions of the Wheeler torque wrenches. When I put a red dot sight on a pistol I did not feel confident in the torque value that was actually applied. This led me to order a few Fix It Stick torque limiters, which range for 10 inch-lbs up to 80 inch-lbs.
https://smile.amazon.com/gp/product/B015S8WWS6
A semi-complete set of limiters costs over $500. This is uber OCD, and may be overkill for some gun owners. However, for a competitive rifle shooter who needs to adjust his scope at the range, it may be appropriate vs. carrying a complete set of tools.
Uh, yes, I know how the "book way" to use loctite.  There are also other ways to utilize based on experience. . .

I have a set of Fix-it-Sticks.  The dedicated limiters, not the adjustable ones (the ones you linked).  I also have a Vortex and NF ones to check.  They are pricey, but needed to eliminate variables.