Rifle Scopes  Nightforce told me to use 100in/lbs on ring clamps - it broke

beetroot

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Good example of how torque wrenches used blindly can be more trouble than just tightening by feel.

It pays to think about what you are doing when using a torque wrench. If it feels like you are going tighter than what you feel is right theres a good chance something is wrong.
60 in/lbs is more than enough for the cross bolts for most rings.
 

Gil P.

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Yeah one of them did fine at 100in/lbs the other one snapped at probably 90ish
I read the manual on a set of 6 screw NF rings I had. They specify 100 inch pounds for the rail clamp nuts. I never tightened them that tight, it didn't seem like a good idea. I bet if more people followed that torque rating we would hear about a lot more broken NF rings.
 

Devildog

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I’m not going to pile on but get yourself some fix it sticks. And learn by your mistakes, owe by the way you might not want to announce them around here the sharks like fresh blood lol. Good luck!
 

jsimonh

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Just to defend the OP a little since I'm not sure whats going on with some of the replies. He followed the Nightforce recommendation for the crossbolt and it broke. I did the same thing and if you search for about 30sec on Google this is not an uncommon thing with the 6 screw rings that call for 100 in/lbs on the cross bolt.
 
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ormandj

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Just to defend the OP a little since I'm not sure whats going on with some of the replies. He followed the Nightforce recommendation for the crossbolt and it broke. I did the same thing and if you search for about 30sec on Google this is not an uncommon thing with the 6 screw rings that call for 100 in/lbs on the cross bolt.

A lot of the problem has to do with knowing how to properly apply that much torque on something with multiple bolts, you don't just go bolt by bolt and go to 100inlb in a single operation, you need to gradually tighten them in a pattern (try to stagger, so you aren't tightening adjacent bolts) to lower torque values and step your way up (say 30 on all bolts/60 on all bolts/90 on all bolts/100 on all bolts if your target is 100). Additionally, a lot of people don't know how to properly hold a torque wrench and apply even steady pressure, so they significantly over-torque bolts.

Finally, some people make the mistake of using thread locker then torquing to max specification, which leads to a significantly different outcome. You need to reduce torque by ~20% if using thread-locker, and 25% for other types of lubricants, if not more.

Either way, helicoils to the rescue for OP.
 

ormandj

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There is only one cross bolt per ring, can't really rotate from bolt to bolt when there is just one but I do agree with almost everything else.

I should have paid more attention, I assumed this was a solid mount, not individual rings. The rest of the advice still applies aside from staggering the torque across multiple bolts! Sorry OP for the slightly off-topic info, but maybe it'll help someone else. :)
 
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M8541Reaper

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    Fucking basement-dwelling amateurs and wanna be operators. You don’t need torque wrenches and fancy tools to mount shit. Just tighten the caps until there isn’t a gap between the caps and base. For the crossbolts, just tighten them hand-tight + 1 full wrench turn. There’s a recoil/set lug on the bottom so it won’t go anywhere. If you’re running MIL/MIL, this is all you need to do. MIL stands for military so it’s military grade and can handle these specs. If it’s MOA/MOA, it’s fucked. If MIL/MOA, it’s gender-confused and shouldn’t be used for anything.

    OP,
    Accidents happen and while it sucks, it’s a learning experience. Obviously you meant in/lb and not ft/lb. NF customer service will take care of ya.

    Happy turkey day you disgusting children. 🍻
     

    1moaoff

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    Just to defend the OP a little since I'm not sure whats going on with some of the replies. He followed the Nightforce recommendation for the crossbolt and it broke. I did the same thing and if you search for about 30sec on Google this is not an uncommon thing with the 6 screw rings that call for 100 in/lbs on the cross bolt.
    They call for in/lbs not ft/lbs he clearly stated he tighten to ft/lbs.....

    Many people hear in/lbs but think ft/lbs because they dont deal in these things often or assume its the same thing as the torque bar they buy at lowes... its not the same
     

    Krob95

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    What???? You said 150ftlbs!!!!! Im sorry but I think you are digging a hole.
    Issa joke. Obviously not torquing anything gun related in ft lbs. Except barrels. Barrels get the ft-lb treatment. I don’t even own a ft lb torque wrench currently as I’ve never needed it. But I am very familiar with them and what 150 to 600+ ft-lbs of torque feels like (worked in a mechanic shop and now the oilfield).


    Jokes sometimes don’t translate well over the internet, sorry bout that.
     

    jsimonh

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    They call for in/lbs not ft/lbs he clearly stated he tighten to ft/lbs.....

    Many people hear in/lbs but think ft/lbs because they dont deal in these things often or assume its the same thing as the torque bar they buy at lowes... its not the same

    Shit I meant in/lbs... my torque wrench doesn't do ft/lbs it's not that big. Sorry, I can see how you're all confused. Seems like the nut was problematic because the other one didn't care and it got to 100in/lbs without a problem

    Gotta read past the first post sometimes. I get the obviously funny responses but there are some straight up dumb post in this thread. It is entertaining though!