Spuhr QD mount torquing

[Near miss]

I decided to make this for anybody looking for information about torque for Spuhr QD scope mounts.

Spuhr recommends 5Nm / 44inlb for the rail mounting screws.

I have a Hazet 0.6 to 9Nm adjustable torque wrench and I have few times tried torquing it higher than what I am using it now.

So yesterday I thought to experiment it and tested how high can I go. I started from 5Nm and could not even move either one. Dropped to 4Nm and it started to seem possible..

The result was 3Nm / 27inlb front and 2.8Nm / 25inlb back, this is probaly result of the mount attaching to the hand guard rail in the front. But these torques are tight and also make it possible to install the mount like it should be, easy and fast!

Having changed torque values, I went to range and was ready to spot the impacts in the snow behind the target.. And noticed the zero was unchanged. So I guess the torque is not that important, as long as it is tight enough.

So there, Spuhr QD certainly is quite well made. Not only could it take being taken off and back on without impact on zero, it did not mind me retorquing the screws tighter.

 

[M8541Reaper]

Did you get the 5Nm/44inlb from a spec sheet or an email to them? I looked through the spec sheets and didn't see this listed, but I might have missed it. I you have it, could you share it?

I never put hands on a QD version of theirs but do you know if it is possible to remove the QD and run a standard mount clamp bar? As in all you'd have to do is buy a new (standard) clamp bar/cross bolts and then swap em out. Not that there would really be a purpose to do so, but really just curious IF it COULD be done by the user.

[Disclaimer: This was a random shower thought]

 

[Near miss]

Did you get the 5Nm/44inlb from a spec sheet or an email to them? I looked through the spec sheets and didn't see this listed, but I might have missed it. I you have it, could you share it?

I never put hands on a QD version of theirs but do you know if it is possible to remove the QD and run a standard mount clamp bar? As in all you'd have to do is buy a new (standard) clamp bar/cross bolts and then swap em out. Not that there would really be a purpose to do so, but really just curious IF it COULD be done by the user.

[Disclaimer: This was a random shower thought]

Good questions. I googled and I think the instructions that came with it also mentioned it.
But nowhere is mentioned how much the QD needs.

I do not think installing the clamp with screws is possible, the basic mount uses 4 screws whereas the QD has 2 QD levers / screws.

Even though the the clamp could be removed and the basic one installed, I suspect that the holes would not align.


Edit:
Added the image of the instructions that came with the mount, citing torques to be used.

 

[M8541Reaper]

Good questions. I googled and I think the instructions that came with it also mentioned it.
But nowhere is mentioned how much the QD needs.

I do not think installing the clamp with screws is possible, the basic mount uses 4 screws whereas the QD has 2 QD levers / screws.

Even though the the clamp could be removed and the basic one installed, I suspect that the holes would not align.


Edit:
Added the image of the instructions that came with the mount, citing torques to be used.
View attachment 7522534

Thanks for the picture. Seems they just haven't updated the spec sheet they have on their product page.



EDIT:
Spuhr confirmed that mounting methods cannot be swapped between.
FYI: Their CS team is on point. Had a response, with a comparison picture of the two models, within 3 minutes.

 

[Near miss]

I also marked QD screws placements to see if they move. The one in the front has moved for 1/8 of a turn. I have taken it off and back maybe 15 times. Possibly 0.1 mil throw in elevation, but I have changed shooting surfaces from soft to hard.

I ordered some Vibra-tite and I will threadlock them in place to keep things simple. I chose Vibra-tite so if I want to later on put it on to another rifle and it needs to be tighter, I can retorque it without reapplying the stuff.

 

[wake.joe]

Thread bump. Sorry.

How is this working for you? I torqued my Spuhr 30mm QD mount to 25inlbs and it’s still too tight to even use the QD levers.

What’s the point? I feel like I should have just stuck with regular four screw Spuhr mount.

 

[Night Vision Viking]

I typically use the standard Spuhr mount, but the QD I have works great as well. Use if for my NV scopre.

 

[Near miss]

Thread bump. Sorry.

How is this working for you? I torqued my Spuhr 30mm QD mount to 25inlbs and it’s still too tight to even use the QD levers.

What’s the point? I feel like I should have just stuck with regular four screw Spuhr mount.

I checked my screws few days ago by trying to tighten them by hand. No movement, so the vibratite seems to have taken a good grip.
So I would say it is good to go, blue loctite could have been even more secure but so far it has held on very well.

As a base recommendation I would suggest to use this way of attaching it:
*I am no expert, you are a fool to listen to my advice but here we are
1. Loose the screws if you cannot open the levers by hand.
2. Take off the mount, clean / wipe all mating surfaces, also any oil from screws.
3. Put the mount on rails, levers opened.
4. Tighten the screws until levers do not go down with easy thumb pressure.
5. Start to loosen screws until the lever goes down with easy thumb pressure. Pay attention that the last portion should go down smoothly, with even force all the way. There should not be need to force the last bit of movement.
6. Take off the mount few time and put back, test that the results are repeatable.
7. Take a sharpie and a ruler, mark the position of screw.
8. Apply threadlocker.
9. Tighten to the marked position.
10. Let the threadlocker cure with the mount secured on the rail.

Bonus: always push the optic forward while mounting it, should eliminate all movement from recoil and at the same time offer a repeatable way of attaching it.

 

[Glassaholic]

I checked my screws few days ago by trying to tighten them by hand. No movement, so the vibratite seems to have taken a good grip.
So I would say it is good to go, blue loctite could have been even more secure but so far it has held on very well.

As a base recommendation I would suggest to use this way of attaching it:
*I am no expert, you are a fool to listen to my advice but here we are
1. Loose the screws if you cannot open the levers by hand.
2. Take off the mount, clean / wipe all mating surfaces, also any oil from screws.
3. Put the mount on rails, levers opened.
4. Tighten the screws until levers do not go down with easy thumb pressure.
5. Start to loosen screws until the lever goes down with easy thumb pressure. Pay attention that the last portion should go down smoothly, with even force all the way. There should not be need to force the last bit of movement.
6. Take off the mount few time and put back, test that the results are repeatable.
7. Take a sharpie and a ruler, mark the position of screw.
8. Apply threadlocker.
9. Tighten to the marked position.
10. Let the threadlocker cure with the mount secured on the rail.

Bonus: always push the optic forward while mounting it, should eliminate all movement from recoil and at the same time offer a repeatable way of attaching it.

I do similar up to #6 but I have not thought to use a threadlocker. Tell me more about the properties of vibratite and being able to re-torque without having to re-apply.

 

[Near miss]

I do similar up to #6 but I have not thought to use a threadlocker. Tell me more about the properties of vibratite and being able to re-torque without having to re-apply.

It is supposed to act as high viscosity agent between the threads, so it should allow up to 5 times of readjusting. So it is very different from loctite, which cements in. The vibratite is more like hot gluish stuff.

I remain sceptical but hopeful, I have not tried readjusting it yet, but I am happy that it has kept the screws in place, which is the primary goal.

I used it in some other case and I remember it held few times. But I have noticed that loose threads allow more of it to enter, tight threads just peel most of it off (it is first applied and let to dry, and only then screwed in)

I tend to think that as long as it does not escape from the screw threads, it should continue to work.

 

[Thriller]

Who cares torque it to specs, mark w paint pen and move on. I don’t shoot w anyone who moves scopes around to different rifles. What job are you doing with it that requires a qd mount to begin with??

 

[Glassaholic]

What job are you doing with it that requires a qd mount to begin with??

my rifles fit in the hard cases much better without scopes attached, sure I could just bring my torque wrench but there’s always this thought of “what if I forget it”. I like toolless features

 

[Near miss]

Who cares torque it to specs, mark w paint pen and move on. I don’t shoot w anyone who moves scopes around to different rifles. What job are you doing with it that requires a qd mount to begin with??

I use the same scope for 22LR too. Also, cleaning the scope lenses is a lot easier done with QD mount.