How Much Torque?

[gbflyer]

Some good info here:

http://bordenrifles.com/wp-content/uploads/2021/11/ScopeBaseTorqueSpecs.pdf

I have seen bases TIG welded to the receiver. That ends the screw torque and movement argument.

 

[redneckbmxer24]

What? You absolutely can tighten good 6-48 base screws to 20 in-lbs. There can’t be an across the board suggested torque because every company has different strength/quality screws. Hence why I said I use the included wrench until I feel it is about to strip or give.







And you know this because you have tried? There’s a couple dozen people from this board alone that have seen what I do to my rifles, and what they can do to them without losing zero.

Legitimate question- how is that you are so confident in beliefs that you haven’t tried, tested, or validated?

You stated that 20-30in lbs isn’t enough. 30 in lbs exceeds the ratings on 6-48 screws. Yes they will take 20 in lbs and they will take the wet. You said that isn’t good enough. Go back and read your own post.

I’ve broken enough screws to know.

 

[redneckbmxer24]

This guy comes here asking for proper torque specs to use to mount what he’s got and you guys go off the rails with some ridiculous shit to try to bomb proof a rifle. The guy has a sub $1000 rifle, glass, and mount combo, I highly doubt he’s looking for advice on how to be able to tow his rifle to the range or hunt spot bouncing down the road on a chain.

 

[Formidilosus]

This guy comes here asking for proper torque specs to use to mount what he’s got and you guys go off the rails with some ridiculous shit to try to bomb proof a rifle. The guy has a sub $1000 rifle, glass, and mount combo, I highly doubt he’s looking for advice on how to be able to tow his rifle to the range or hunt spot bouncing down the road on a chain.

So how is it that taking a thing who’s sole purpose is to land a bullet in conjunction with a reticle, and making that as likely to happen as is possible is “ridiculous shit” to bomb proof a rifle?


Tell me logical reasons why I wouldn’t, or shouldn’t seek to remove as many variables as possible from the rifle system that I can? What does not removing potential sources of losing zero gain me? Why should I except less reliability and less resistance to accidents?

 

[Kurts86]

For what it’s worth I can’t find an engineering reference for a #6 screw torque above 29 inch lbs with most around 22-25 lbs. At 29 in-lbs with dry steel you generate 1050 lbs of clamping force and the screw stress is 105 KSI. The surface area of the minor thread is 0.01 in^2 on a #6 screw.

Grade 8 bolts are typical good for 150 KSI so your #6 screws should start snapping around 42 in-lbs.

65 in lbs on a #6 screw is going to create 239 KSI of stress which is well past the sound of pop.

 

[redneckbmxer24]

So how is it that taking a thing who’s sole purpose is to land a bullet in conjunction with a reticle, and making that as likely to happen as is possible is “ridiculous shit” to bomb proof a rifle?


Tell me logical reasons why I wouldn’t, or shouldn’t seek to remove as many variables as possible from the rifle system that I can? What does not removing potential sources of losing zero gain me? Why should I except less reliability and less resistance to accidents?

Because it’s in unreasonable expectation with certain equipment.

You gave the guy advice to overtighten his screws which is terrible advice. Then to buy a rifle with a built in rail which he probably isn’t going to do because you say so.

He asked what to torque his setup to.

 

[Antares]

I'm degreasing rail and receiver with acetone, applying Marine Tex epoxy w/ no release agent, snugging screws, letting epoxy cure, degreasing screws, then torqueing to 25 in/lb with blue Loctite.

@Formidilosus, how warm and fuzzy does that make you feel? On a scale of one to warm and fuzzy? Joking aside, I would like to hear your opinion on that procedure.

 

[Formidilosus]

Because it’s in unreasonable expectation with certain equipment.

You argue and disagree constantly with “trying to bombproof” a rifle; or that there are differences between scopes abilities to fend use and hold zero. I have repeatedly offered at no expanse to you, the ability to prove that all the scopes are basically the same, and that none of them can hold zero from drops. After initially saying you would, you have avoided that.

Now you are arguing that it is stupid to try to make a rifle base not move. I asked to give me a logical reason why I, or anyone, should accept less reliability or durability? Give me a logical reason why I should choose to mount a base with a technique that has a higher likelihood to lose zero.

You gave the guy advice to overtighten his screws which is terrible advice. Then to buy a rifle with a built in rail which he probably isn’t going to do because you say so.
He asked what to torque his setup to.

And I stated a reality that 20in-lbs has a relatively high likelihood of losing zero. And I how I do it to reduce the possibility of the base moving. Much like the scopes, I’ll do this in front of you.

 

[Formidilosus]

I'm degreasing rail and receiver with acetone, applying Marine Tex epoxy w/ no release agent, snugging screws, letting epoxy cure, degreasing screws, then torqueing to 25 in/lb with blue Loctite.

@Formidilosus, how warm and fuzzy does that make you feel? On a scale of one to warm and fuzzy? Joking aside, I would like to hear your opinion on that procedure.

You should have little to no issues with the base moving doing that. That’s basically what Tikka does on the CTR/etc. Glueing it down removes most/all of the stress from the screw’s themselves.

 

[TheHammer]

You stated that 20-30in lbs isn’t enough. 30 in lbs exceeds the ratings on 6-48 screws. Yes they will take 20 in lbs and they will take the wet. You said that isn’t good enough. Go back and read your own post.

I’ve broken enough screws to know.

While I agree with certain things you’ve stated here and other places. I didnt catch him mentioning a screw size, in fact what I took from it is the sizes mentioned are not utilized based on experiences of failure. If you note how certain things are worded there is only experience by hand being shared. While you me or the next guy can disagree with an opinion or method, it doesn’t make it wrong if his results show otherwise. You and I both look for an exact spec as opposed to an opinion of feel by experience. Randy Selby demonstrates some of the same methodology as what Formidilosus is explaining. (As long as he doesn’t start to discuss the 7mm wapiti express) While I look for a number and exact process, he and others developed a mythology to apply where seen fit.

 

[gbflyer]

I'm degreasing rail and receiver with acetone, applying Marine Tex epoxy w/ no release agent, snugging screws, letting epoxy cure, degreasing screws, then torqueing to 25 in/lb with blue Loctite.

@Formidilosus, how warm and fuzzy does that make you feel? On a scale of one to warm and fuzzy? Joking aside, I would like to hear your opinion on that procedure.

Roughing both degreased surfaces to be bonded together with 80 grit will promote a good handshake for something that is intended to be permanent.

 

[tony]

Can I ask what ring caps are? Is this the top ring?
Integral/integrated same thing? Speaking for rails. Are there rifles where this is machined into the receiver?
Just planning for a future rifle and learn something here daily

 

[Antares]

Can I ask what ring caps are? Is this the top ring?
Integral/integrated same thing? Speaking for rails. Are there rifles where this is machined into the receiver?
Just planning for a future rifle and learn something here daily

You got it.

 

[PNWGATOR]

Because it’s in unreasonable expectation with certain equipment.

You gave the guy advice to overtighten his screws which is terrible advice. Then to buy a rifle with a built in rail which he probably isn’t going to do because you say so.

He asked what to torque his setup to.

Formidilosus’ advise is spot on.

FWIW It might not be a bad idea to type less and read more.

Just sayin.

 

[MallardSX2]

My family and I for 50 years tightened bolts to snug and gave them a 1/4 turn and killed more game than ehd….


I think people may be overthinking things a bit. Lol

For the record I do use a torque wrench now. But I can’t tell any difference in accuracy lol

 

[Drenalin]

I appreciate everyone’s insight. I’m not planning to abuse the rifle, but I am going to use the piss out of it, assuming it shoots well. It’ll ride in the truck a lot, probably get bumped around a fair bit, and might even get dropped. I don’t want to have to baby it, and I definitely don’t want anything to move.

I didn’t notice anyone suggest I should replace the rifle, but the point was made that an integral rail is a better solution…this seems to be born out by the back and forth of how fragile the rail screws (likely) are. So I’m going to basically do as @Antares outlined:

1. Degrease everything with brake cleaner.
2. Sand the top of the action and bottom of the rail; clean again.
3. JB Weld the rail to the action; blue Loctite those screws in, turn until snug then add 1/4 turn. No idea how much torque that’ll be, at this point I don’t think I care.
4. Attach rings to base; going to with blue Loctite here too, snug then add 1/4 turn.
5. Same as above for ring caps.

Only question I’ve got now, obviously I don’t want any release agent on the rail or action, but I’ll have to put those screws in while the epoxy cures. So I need release agent on the screws, right? I’m thinking this needs to be easy to clean off the screws and out of holes after epoxy cures, so I’m leaning toward cooking spray.

 

[Antares]

Yes. Put release agent on the screws. I use neutral shoe polish, but all kinds of stuff works.

 

[SDHNTR]

I appreciate everyone’s insight. I’m not planning to abuse the rifle, but I am going to use the piss out of it, assuming it shoots well. It’ll ride in the truck a lot, probably get bumped around a fair bit, and might even get dropped. I don’t want to have to baby it, and I definitely don’t want anything to move.

I didn’t notice anyone suggest I should replace the rifle, but the point was made that an integral rail is a better solution…this seems to be born out by the back and forth of how fragile the rail screws (likely) are. So I’m going to basically do as @Antares outlined:

1. Degrease everything with brake cleaner.
2. Sand the top of the action and bottom of the rail; clean again.
3. JB Weld the rail to the action; blue Loctite those screws in, turn until snug then add 1/4 turn. No idea how much torque that’ll be, at this point I don’t think I care.
4. Attach rings to base; going to with blue Loctite here too, snug then add 1/4 turn.
5. Same as above for ring caps.

Only question I’ve got now, obviously I don’t want any release agent on the rail or action, but I’ll have to put those screws in while the epoxy cures. So I need release agent on the screws, right? I’m thinking this needs to be easy to clean off the screws and out of holes after epoxy cures, so I’m leaning toward cooking spray.

You are on the right track. With your proposed rifle and system, and in the absence of an integral rail, it’s about the best you can do. This thread went unnecessarily sideways.

Apply release agent thoroughly on screws and inside screw holes. I like wax better, especially in the screw holes as it serves as a plug to keep errant epoxy out. The wax easily cleans up, especially with a little heat, and the screws will push most of it out. Cram a paper towel into the action to catch any excess spooge out the bottom of the receiver holes.

FWIW, for mounting rails on the receiver: with 6-48 screws I go 20” lb. On 8-40 screws I go 25” lb. On most ring caps I go 20” lbs, unless the manufacturer states more. If the manufacturer states less, I disregard and go 20 anyways. Many ring manufacturers are scared of crushing scope tubes. Don’t use crap scopes and that’s not an issue. On ring base cross bolt screws I follow the ring manufacturer recommendations. Each design is a bit different. I degrease everything and use blue loctite on everything.

 

[mxgsfmdpx]

I've always tightened down my ring bases to the action until the little Allen or torques L wrench that comes with the rings, bends on itself from the torque. Haven’t stripped any threads or screw heads yet. Also haven’t had any ring bases come loose from an action with this method plus blue loktite.

 

[Drenalin]

Apply release agent thoroughly on screws and inside screw holes. I like wax better, especially in the screw holes as it serves as a plug to keep errant epoxy out. The wax easily cleans up, especially with a little heat, and the screws will push most of it out. Cram a paper towel into the action to catch any excess spooge out the bottom of the receiver holes.

Just watched a YouTube video where the guy used playdoh; wax or doh, it’s a good point. Thanks!