Rifle Scopes do you check your torque values?

[Walter Haas]

Guys, when I first mounted my scope I used an accurate torque screwdriver to torque the mount screws and the tube screws. Is there a need to re-check this once in awhile? I just assumed I'm done, but I did notice my screw-on "shade" I think its called, screwed onto the scope to shade the lens, was loose after a couple hundred rounds. Got me to thinking whether mounting screws need to be "re-torqued". What's your experience with this?

 

[Trigger Monkey]

Witness marks can mitigate the need for checking torque.

That being said it's not a bad idea to check the fasteners periodically but I wouldn't be checking them after every range trip or anything unless I was having an issue.

 

[Threadcutter308]

Guys, when I first mounted my scope I used an accurate torque screwdriver to torque the mount screws and the tube screws. Is there a need to re-check this once in awhile? I just assumed I'm done, but I did notice my screw-on "shade" I think its called, screwed onto the scope to shade the lens, was loose after a couple hundred rounds. Got me to thinking whether mounting screws need to be "re-torqued". What's your experience with this?

Blue (Never Red) Loctite your cap screws, torque them as recommended and you shouldn't have issues. I've done that, gotten lazy and only checked them once in a while. They may tighten up a little on subsequent checks, but nothing of any consequence.

 

[clcustom1911]

I torque down, then recheck after 100-150 rounds. I havent checked the torque on my 7mm RemMag for almost 1000 rounds because I haven't really had a reason to. Zero hasn't shifted, etc. If you lose your zero after initial torque down... then that's definitely one area to check.

 

[Dthomas3523]

I usually take everything apart when I clean, so that’s every 100-300 rnds somewhere.

But, say I’ve already cleaned, going to range to zero/dope before a match, I’ll hit everything again with torque. Then before the match I’ll do it again. More for piece of mind than anything.

Takes 5min or less with fix it sticks.

 

[Rob01]

You have to watch repeatedly torquing without loosening. You can snap screws. Story my teammate tells of shooting a sniper match when in the Corps and the army team every morning used to put a torque wrench to their action screws. Last day their action screw snapped. They probably did it all the time and it just went. So if you feel the need to check it then first loosen it and then retorque. Do one ring cap at a time and nothing will move.

Honestly though I rarely check mine. I have ring caps I haven't checked in years. Never a need. Haven't checked my scope bases in many years. They were all installed correctly with loctite and never have loosened.

 

[dgheriani]

I just witness mark everting so I can tell at a glance if anything has come loose.

 

[Dthomas3523]

Good point. I also believe you may only be verifying friction at times and not torque when you check torque with torque wrench.

Where are the engineers when you need them? @308pirate

 

[TriggerJerk!]

Blue (Never Red) Loctite your cap screws, torque them as recommended and you shouldn't have issues. I've done that, gotten lazy and only checked them once in a while. They may tighten up a little on subsequent checks, but nothing of any consequence.

^^^^^^^This!

 

[beetroot]

If they are torqued up correctly they shouldn't need to be re-torqued all the time.
If you are having issues with them backing out you need to use some sort of thread locker.

You don't go check the torque on all bolts on your car once a year, unless something is wrong it's unnecessary.

Witness marks are a great idea, if you are worried about them coming loose or moving then that's an easy way to tell.

 

[Walter Haas]

Witness marks can mitigate the need for checking torque.

View attachment 7282648

That being said it's not a bad idea to check the fasteners periodically but I wouldn't be checking them after every range trip or anything unless I was having an issue.

Forgot about witness marks. Thanks!

 

[308pirate]

I also believe you may only be verifying friction at times and not torque when you check torque with torque wrench.

Most of the torque applied to a threaded fastener (75 - 90% typically) is spent overcoming friction. The majority of that friction comes from the final alignment of the mating parts and from the contact between the bolt head and the surface under it. The remainder is consumed in the threads as they rotate relative to each other, where clamping force (what really matters) is created.

And oh yeah, you can't check a bolt by applying rated torque. You need to slightly loosen it then torque it back up to standard.

 

[mtnhunter22]

I just witness mark everting so I can tell at a glance if anything has come loose.

Another vote for this

 

[10ring'r]

Anything I have doubts about, as far as slipping goes, a silver "Sharpie" is your friend.
Mac

 

[308pirate]

When you get technical everyone's all thumbs up but when I get technical its overreaching physics bullshit that's worthless.

knowledge + experience = wisdom

 

[spife7980]

Ha! I was going to say applicable knowledge vs random musings lol.

 

[E. Bryant]

And oh yeah, you can't check a bolt by applying rated torque. You need to slightly loosen it then torque it back up to standard.

This bears repeating. Rob's story about breaking an action screw by repeatedly checking the torque suggests that certain types of "snap-over"/click-type torque wrenches may indeed act as a impact driver if the wrench is not used properly. I've also got some experience with putting those type of wrenches on a factory floor with, shall we say, inconsistent results from operators who think that if one click is good, then 15 or 20 clicks is even better.

Witness marks are the way to go if one doesn't want to take things to the (il)logical extreme with safety wire; it's deemed to be an adequate and effective measure for many areas of a race car that don't merit mechanical retention. But if someone wants to get serious:

Socket Head Cap Screw Alloy Steel-Drilled | Aircraft Spruce

Socket Head Cap Screw Alloy Steel-Drilled Socket Head Cap Screw-Alloy Steel-Drilled

www.aircraftspruce.com

Blue Loctite (or better yet, Purple) is a reasonable counter-proposal. Or if one is not a complete ham-fist, it's also possible to apply light hand torque to quickly determine if something has loosened (in my experience with rifles, loosening usually doesn't mean that a ring screw backed off from 18 in-lb to 12 in-lb, but rather than it's gone from "properly snug" to "way too loose").

 

[DustBun]

@308pirate response is right on. Breakaway torque is almost always higher that actual torque.

I do not use Loctite on my Spuhr mount. I apply the specified amount of torque "correctly", there is a right way to apply torque, to the fasteners and witness mark. I check the witness marks before heading to the range. I have not had any loosening.

 

[Harman117]

Torque for bolts?

Nah, I use an ultrasonic bolt tension meter. Tension is what you actually want to measure; torque is dumb for this application.

(I actually just follow manufacturers instructions and torque accordingly. Using witness marks is the way to go)

 

[Mute]

Just use witness marks.

 

[beetroot]

This bears repeating. Rob's story about breaking an action screw by repeatedly checking the torque suggests that certain types of "snap-over"/click-type torque wrenches may indeed act as a impact driver if the wrench is not used properly. I've also got some experience with putting those type of wrenches on a factory floor with, shall we say, inconsistent results from operators who think that if one click is good, then 15 or 20 clicks is even better.

Witness marks are the way to go if one doesn't want to take things to the (il)logical extreme with safety wire; it's deemed to be an adequate and effective measure for many areas of a race car that don't merit mechanical retention. But if someone wants to get serious:

Socket Head Cap Screw Alloy Steel-Drilled | Aircraft Spruce

Socket Head Cap Screw Alloy Steel-Drilled Socket Head Cap Screw-Alloy Steel-Drilled

www.aircraftspruce.com

Blue Loctite (or better yet, Purple) is a reasonable counter-proposal. Or if one is not a complete ham-fist, it's also possible to apply light hand torque to quickly determine if something has loosened (in my experience with rifles, loosening usually doesn't mean that a ring screw backed off from 18 in-lb to 12 in-lb, but rather than it's gone from "properly snug" to "way too loose").

I think lockwire is the way to go for scope rings.
That way you can catch yourself on the wire tail in a match and drip blood all over your scope and rifle.

 

[10ring'r]

Witness marks are the way to go if one doesn't want to take things to the (il)logical extreme with safety wire; it's deemed to be an adequate and effective measure for many areas of a race car that don't merit mechanical retention. But if someone wants to get serious:

One of the worst jobs in the aircraft maint. field, was...Safety Wiring! You'd be surprised, how tight an area, that s.w. can be used and/or applied. Talking about being a "contortionist". The last time I used that method of securing nuts & bolts, it was on my race bikes and off-road vehicles. Don't miss it, but it IS an option. Mac

 

[Big_Kumar]

I must be in the minority, but I don’t use witness marks. I am what some would consider “fairly particular” about assembly and work under the assumption that individual components will work as designed.

If I never see lock wire again, it will be too soon. Lock cable is less offensive, but I still don’t like it. I still have scars from lock wire.

 

[Trigger Monkey]

the assumption that individual components will work as designed.

Is the thought process that occupied the mind of many leading up to a failure of some sort, just sayin'.

 

[Big_Kumar]

I completely understand where you are coming from and would agree to a certain extent. I guess I should have specified that nothing is trusted until it has been tested. Trust without verification is asking for disappointment. Every person has a personal threshold of what they are willing to accept or what gives them peace of mind. If witness marks alleviate worry, then they are worth using.

My personal process works for me, but I am not suggesting that it is for everybody. I will offer that it is a proven system and is much more comprehensive than suggested by two sentences.

 

[Steel head]

Dab of vibra tite and torque to spec and forget about it.

 

[2aBaC̶a̶]

German torque spec.

Gudentight

and what Steel said.