Home Forums Hunting & Shooting Hunting Optics Scope mounting to maintain zero....

After multiple requests for an explanation of how to mount a scope in order to have the lowest possible chance of loss in zero, I took some pics of what I do with a rifle when I get it and how I mount scopes (or anything with screws).

To start- a bit of background of why I say what I say.

I am a backpack hunter. What I write below is tailored to hunting.

Having sid that, I work at a place that fires a lot of ammo. I see over half a million rounds a year on average get fired. 90% of those rounds are tracked. Weapon zeros are checked nearly daily, scopes, mounts, rifles, ammo, etc, are being tested constantly. If a rifle has even a .5 MOA shift in zero we will see it almost immediately. My thoughts are this- scopes are an aiming device. They are a container to hold my reticle so that I can hit targets. I do not care about scratches, dings, or ring marks. I do care that the bullets go where the crosshairs are pointed. My first requirment is that the rifle stays zeroed through use. To do that the mounts, rings, and action screws can not come loose.

The #1 reason that we see for loss of zero is failure to mount optics correctly. The #2 reason is the optics themselves failing. This applies to hunting rifles as well. #2 has been discussed several times so I will leave that one alone.


Here we go....


Some principles:

1) Things don't shoot "tight", they shoot "loose".

2) Oil and greas helps things move/keeps things from sticking together (this includes oil from fingers)

3) Under torquing screws helps them shoot loose. Over torquing breaks things.

4) Manufacturers apply oil to every metal component to keep it from rusting. Every screw, every base, ever ring has oil on out of the box.

5) Manufactures generally offer info that keeps customer service calls down. When it comes to scope mounting- Ring manufactures generally get calls for rings and mounts "marking" scope tubes. Scope manufactures generally get calls for crimped scope tube causing erector issues. The first is a bit of improper alignment and over torquing, the second is overtightening and fragile scope tubes.

6) The farther apart the rings are, the better support for the scope tube. Ring spacing is a thing.



All the parts for those that will ask-

Howa 6.5 Grendel
SWFA SS 3-9x42mm
Seekins Pic Rings
Burris XTR Bases
Hand tools
Acetone or break cleaner
Blue Loctite, paint pen, or finger nail polish
Napkins and Q-Tips
Scale because someone will ask....









Take the rifle apart. Brand new out of the box. That is oil on the screw. Aka- it will come loose Aka- loss of zero.







Spray brake cleaner or dip the action screws in acetone. Wipe with a clean rag.






Next is the action base holes. Spray/wipe down the action and inside the screw holes to remove oil.







This is oil on tbe Q-tip. Aka- loss of zero.







Next is to wipe down the bases. Oil here too.








Cont....

Next the base screws. Oil here.






After cleaning, apply thread locker to both screw and screw hole






Tighten to whatever you deem appropriate. The small end of the wrench works fine, with the long end for a finish.








When tightened...








Next the rings...






Take apart apart me wipe the caps, and clean screws and screw holes.








Cont....

Cont.....

Degrease base.




Thread lock base screw and holes






Tighten appropriately and if using Picatinney or Weaver rings push rings forward into the lug.





Degrease scope tube, ring cap screws, and apply thread locker to screws and screw holes






Cont....

Just get the rings screw not quite snug and set eye reload and align the reticle. Whatever way you do not is fine if it works. I mount a lot of scopes and can eyeball the vertical posts with the butt stock very close.




Then ensuring that the scope doesn't twist, tighten the ring screws. 18in-lbs is what I generally do. Any less than about 16in-lbs and you sometimes see slippage. The little end of the wrench is good for this.








Once that is complete spin the power ring and parralax knob if it has one and spin the turrets up and down. You're just looking for binding or anything weird. If it's good, you're done.











. Cont......

I’m seeing a common theme here

Now I really don't like things to move. So I go a step further and seal around the screws with a paint pen or nail polish. This is another layer to keep oil out, and allows at a glance to see if a screw has loosened.







Just a dab around the screw heads will do.









Cont......

This how I do it, and why. Every single problem we have with optics moving, or screws coming loose is due to not degreasing, not using thread locker, and not torquing correctly. What most miss, is that the rifle is a system- bedding, action screws, bases, rings, and scope all matter if your goal is a static zero.

Just to be clear... no lapping, not rubber cement in the rings, no bandaids, etc????

No. Not unless the action is milled/tapped incorrectly. Even then, scopes with tube walls as thick as SWFA/NF/Bushy LRHS/etc, don't tend to suffer the same issues as most scope do when stressed.

Excellent write up!

Nice tutorial, thank you.

Thanks

I’ll keep this in mind.

Great stuff.

Should have a permanent sticky. Thanks.

Thanks for the thread, Form.

Looks like I'm close with my mounting procedure but not close enough.
More cleaning and more Locktite is needed.

Should put this thread into sticky format for later reference.

This should be a sticky. Great write up. Thanks for posting,

Good stuff. Thanks for taking the time.

Thanks for the post....I'll have to admit, I never knew degreasing was so important.

Thanks, need to stock up on acetone

Great write up. I need to start doing that to seal the screws. I clean the oil off but have questioned doing it as base and ring screws ALWAYS end up rusted on my rifles. Maybe the rust helps as a locker?


I'm a fan of Seekins rings. I especially like them with SWFA's because of the ease of lining the end of their etched symbol up with the white dot on the scope as seen in the pic below. So far it's been a quick and easy way to verify alignment with alternating the tightening of sides to opposite corners keeping even tension.

Can the nail polish work as a replacement for blue loctite on the threads as well?

Ok, now for the mil based reticle tutorial......that would be a huge help to a LOT of guys on here that are transitioning from hunting (Plex or BDC) reticles into a mil/milquad reticles and twisting knobs.

I go through ALOTTA StartingFluid as a NIB degreaser and as a 'cleaner. Have lonnnngggggggggggg been a fan of Nail Polish,to keep fasteners fastening and as eluded to,it grants a visual reference. Plus,it gets Whiners to start fhuqking WHINING. Laughing!

On a S/A,I'll often go 1913 rail,mainly for ring spacing,but inclination to boot. 'Horn rings have no fhuqking equal and folks are quick to NOT realize,that all erector travel below zero...is 100% fhuqking USELESS. Hint. An extended 1913 rail is a mandate on itty-bitty Rimfire receivers,when/where they exist(Ruger 77's,being the greatest bane).

No matter the platform,ring spacing is your friend. Hint.




Happiness is a 75MOA extended 1913 rail,barrel chop,some paint and more than a leetle 'polish on nether regions that tend to wander.




'Horn's have the extry surface area and added fasteners,along with copious inclination(or windage if requisite),to do glass more favors than any other approach.




There's Method to the Madness and nothin' goes on by "accident".

I might even shoot some centerfire too.(grin)

Hint.....................





'Mountain Erector/Windshield Flavorings Teaser RINK


The MQ SMOKES the MOA/MOA reticle/erector...but I've got it all and then some.

'Mountain MO-MO Ele/Windtitude RINK


'Horn rings.

1000 Words On 'Horn Rings RINK

Re-'Horn rings.

1000 More Words On 'Horn Rings RINK

Just saying

If only for conversation...............







.

Thanks for the tutorial, I never even thought about degreasing everything before. Might have to invest in some "sinful colors" pink as well

Tag.

Thanks!

Thanks for the effort. Very thorough.

Tag.

Formidilosus,

Before mounting the scope in the rings do you check ring alignment with aligment bars to see if the rings are out of aligment?

There really might be some good information in there if I could only find it. It's just hidden so well among all the profanity and made up nonsense words that I can't sift it out. I just apparently don't speak the same language.

Good write up. I'll just throw out that by far most of the troubles I've seen from scope mounting have been in the base to receiver area. I mounted a 20 moa rail on a friend's savage 110 300 win mag about a year ago, degreased everything with acetone, blue loctite, and torqued to spec with a torque wrench. It shot loose after about 1000 rounds of 215 berger hybrids. It got put back on with red loctite.

Form - good write up. Especially liked the nail polish idea - hadn't thought of that. I've been guilty of over-tightening ring screws in the past. You know, farmer tight is good for everything 😎

This is good. Thanks

I sorta overtighten new screws to kinda set or stretch the threads, back off, then torque.

I'd be interested in that....

That's been done... It can be located. Somehow.

Just saw this from the wayback machine.
https://www.24hourcampfire.com/ubbt...57230/all/Turrets_long_range_real_life_t

thats the way, way back moochine

Form, thank you very much for investing the time in that tutorial. It's a time intensive undertaking. Your style of delivery really resonates with me. I like a straightforward no-nonsense style. If I were a betting man I'd bet that you have military or police training in your background. As I read what you wrote and I looked at the kind of equipment you used, I evaluated my practices and equipment against yours and I am batting about .000. That led me to questions about what I should do from here. So if you will oblige, tell me what you think.

I have a number of Rugers with their integral base and rings. Some on rimfires. None on heavy recoiling rifles. 7mm-08 is the heaviest I have. I don't own a torque wrench. I tighten bases just short of farmer tight and rings pretty damn tight. I can't do anything about the Ruger integral system but I am curious what you think about it as a system. I shoot the rimfires frequently. The 257 Roberts and the 7MM-07 ultralights see about a box a year. Would you disassemble and blue loctite everything? Hell, I already know the answer to that question. So here's the follow-up. How far off of zero would you expect to be after reassembling the right way? I guess we should ask the same question about the following systems as well.

I also have a few rifles mounted in Leupold single dovetail systems? What's your opinion of those?

I have two rifles mounted in Talley lightweights. What are your opinions on those?

I am assuming that you don't like aluminum Weaver style bases, is that correct?

You mentioned that you backpack hunt. Do you use the same heavy bases, rings and scopes on your backpack rifles that you use in your line of work? Are there any lightweight mounting components that you recommend?

I guess my last question is this. How hard is it to disassemble systems using the loctite and nail polish that you use? Any special tools or stuff required?

Man, this place (the fire) has been a wealth of information lately. It seems like folks are investing a lot of time in educating and informing the masses. I appreciate it.

Great writeup, and good visuals on how everything is covered in oil from the factory.

Part of my profession is testing fasteners (meaning screws, bolts, nuts, threaded holes, etc) and I'd like to add one detail if I may: using blue 243 Loctite is better than blue 242, and here's why.
You won't get all the oil out of screw or hole threads with the methods described above, and #243 Loctite still cures correctly in the presence of oil. 242 does not, even though both are "blue loctite". There is no downside to using 243 in scope mounting.


I've taken to using green 680 Loctite under scope bases on bolt actions, mostly as a "belt and suspenders" thing. It has the added advantage of curing in up to .015" air gap, so it'll fill in minor misalignment between the base and receiver if necessary. It does require a little heat and a sharp impact to remove it so it's not appropriate in every situation.

Won't the tip of a soldering iron in little screw heads help when breaking Loctite adhesion?

Near my process short of Loctite'ing the cross bolts to the base (on my old Weaver's) and the final application of fingernail polish. Good read.

Yup that's a handy trick if you need it. Although with blue (either 242 or 243) Loctite and scope mounting screws, you shouldn't need to do that unless they're really overtightened.

That is what I use, and it works well.

Thanks for posting this.

I have always wanted to know what the proper method was for mounting a scope. I now believe I know. I'm still gonna use duct tape, since it's cheap, but at least I know how to do it!!!! Thanks for the informative post.

Excellent post deserving of a sticky.

Great post. One thing baffles me. The now typical rig consists of a $500+ rifle under a $500+ scope and you won't spend $60 on a good inch/lb torque wrench? Seems like the very definition of false economy.

there's more than one way to skin a cat...... just not the same cat..





j/k Thanks for the post..

? Am betting there's plenty of torque wrenches around...

Yeah I would hope so but the "use the small end of the Allen wrench" or "not quite farmer tight" quotes have me worried. I would bet a fair amount of problems would be cured by using a torque wrench.

Non-issue. I believe he's just saying using the tool that way gets you about 18 in/lb - not indicating nor advocating that one NOT use a torque wrench. It was specifically written to torque them. Forms a great guy for writing this stuff up.

Just out of curiosity, what kind of place is this?

thanks,


Okie John

Great post, and I truly appreciate the information.

Just out of curiosity, what kind of place is this?

thanks,


Okie John

Has this been made into a sticky yet?

I'd assumed everyone knew to degrease new machined parts...

My own method:

a). De-grease everything, screws, holes, bases, scope.
b). Mount bases with JB Weld... While likely overkill, I think it's better than Blue Loctite, and provides a monolithic mount. (25 in lbs)
c). Lap Rings.
d). Mount scope in a thin layer of rubber cement.
e). Secure ring halves with Blue Loctite on screws. (20 in lbs)


I do like the idea of nail polish on the ring screws... that's a great idea and a new one to me, though I can't say I've ever found a need for it, it sure can't hurt. I think I'll pass the pink and go clear

I usually use a layer of blue Loctite between scope bases and the action, and it usually works pretty well. That's exactly how I attached the NULA rings (which today are Talley Lightweights) to the first NULA we had, a .270 Winchester that Eileen used for many years until she started getting recoil headaches. After working up a very accurate load with 130 Partitions, the rifle stayed sighted-in for a decade, despite being bounced around in float planes, saddle scabbards, and even a small boat in the Arctic Ocean. Just before hunting season, whether it was started in Montana after antelope or up North after caribou, she'd take one shot from the bench at 100 yards. It would land dead-center, two inches high, and we'd go hunting. The only reason the rifle eventually lost zero is the scope went bad.

If for some reason I want the bases to REALLY stay solid I use Acra-Glas Gel. (Don't think it's works any better than JB Weld, but I have plenty on hand.) Two rifles with Acra-Glassed the bases are my standard scope-test rifle, a Heym .300 Winchester Magnum, and a Mark X Mauser .375 H&H. The .375's bases got epoxied partly because the 98 Mauser action was never really designed for scope bases, and when the bridge is contoured for them there's not much thread-contact for the screws.

But yes, a lot of the time what we think is a scope failing to hold zero is actually movement of the scope-mounts, usually the bases--understandable because they're held on by pretty dinky screws, even when 8-40's. Firmly connecting the bases to the action can really help.

Thank God my Rugers don't have bases....

Kinda tough to tell if the screws have loosened when using clear paint or nailpolish.



Standard practice for fasteners in critical service in industry, air craft, automotive, etc.,

On a hunting rifle, I will bed the bases with Devcon 10110 and I degrease first with my ultrasonic tank. I use green loctite on the screws and use a toothpick to put a drop of Gorilla glue inside the rings. I have never had one move with this method and don't have to use a torque wrench to get it tight enough. I only have one torque wrench that goes low enough and it is Torx type marketed by Warne so it doesn't fit everything. I torque stripe (inspector's laquer or tamper paste- whatever you want to call it) the trigger adjustment screws but not the scope screws. If you degrease them and use green loctite they won't move.

I've been using the same bottle of clear nail polish on trigger adjustment screws since 1998. It's pretty clear, no pun intended, when the paint fails.

I never use Loctite on the ring screws there seems to be enough spring in the rings. When I shoot the rifle the first time, I will check the ring screws after A number of rounds. Then snug them up, they stay tight after that. The bases I will degrease and Loctite.

243 Loctite (surface insensitive) on clean external & internal threads. Same blue loctite on clean surfaces of receiver/ring base. I use a in-lb torque wrench. For cleaning I use PVC solvent.

Problem with the short fasteners we use is there's for practical purposes no fastener stretch.Long fasteners stretch (like a spring) when torqued/tightened properly. This helps with fastener torque retention.

The condition driftless describes (spring in the ring) could provide torque retention.

For assemblies where short fasteners are needed, it is common to see bolted joint designers us spring washers (Belleville washer) to help retain fastener torque.

You seem to have a pretty solid understanding how bolted joints work; not many do. Stretch like a spring is what keeps joints tight, with or without Loctite.

Something to consider though in this application that's different than most bolted joints - the spring in the ring screw joint isn't the screws (in most cases), it's the scope tube and/or the rings. With an air gap between most top and bottom rings, usually we're stretching or compressing the bolted parts before the fasteners.

No matter how much Loctite or Devcon you use, if the scope is a POS you are doomed before you start.

Pretty fly for a white guy

Formi, have you ever had an aluminum picatinny rail fail? I really like the idea of the actions with an integral rail.

Only Chinese knock offs. Aluminum is what I normally choose.

Formidilosus - question...I am following your guide step by step as I mount my new NF SHV 3-10x42 on my LAW Professional 280 ackley. The rifle came with steel 2 piece pic. bases that seem solid and I plan to use them with burris xtr low rings. I realize that 2 piece bases aren't as strong as one piece units, but done correctly should I have any worry about the solidness of the 2 piece steel bases, burris rings, and the NF SHV as a complete system?

You can get 18 inch pounds with the Allen wrench in that configuration? I must be over tightening.

You should be good.








I can get way more than 18 in-lbs with the little end. Most adults get between 16-20 in-lbs doing it that way.

I believe most people are over tightening.

Why am I seeing pictures of scopes with orange tape on them? I must have missed a memo.

I personally don't think there is such thing as over tightening, at least until the screwhead breaks or if you're using steel rings that are just a touch too small or the scope body a touch too big. I can see scope tubes getting crushed in that case.

I welded some steel bases onto a rifle not too long ago, then welded the steel rings to the bases and put a small tack weld on the ring piece joints once I had the scope in place. I honestly can't say I regretted that choice. It is a cheaper play rifle, and a quick touch with an angle grinder would remove the weld if/when I need to get the scope off, but I haven't see any negative to doing that yet.

I do think I will try the nail polish trick on several other rifles I have laying around here though. Good idea.

Form,
Quick question. Are the Burris XTR bases about the best two piece bases out there that work with picatinny rings like the Seekins and Warne Mountain Techs?

In my case, focus lock.

Yes. It doesn't take long to get the screw threads hot enough to melt the adhesive used, even using red loctite. But, don't let it cool before getting the screw out of the hole and the remaining loctite out of the hole and the screw because when it solidifies again it retains the adhesive property. All of the epoxies and the loctites are plastics.

* The blue loctite adhesive bond can be broken by hand. The red loctite needs to be melted.

** I haven't tried the colored nail polish to be a quick check to determine if the scope has slipped in the rings. I plan on doing that as well as putting it on the top of the screws after the screws are all installed and everything is plumb and level.

Great write up mirrors what I do minus a couple steps. I like to coat the scope where the rings clamp with rosin. This will prevent slippage and should it slip you will see a line of the rosin.

I also like to ensure I am tightening the rings down equally. I tighten opposing screws slowly. Eyeing the gap between the ring top and bottom. Once they appear close I use a feller gauge to get a equal gap left and right then I torque to final spec.

Well that's just a whole pile of awesomeness. Bravo!

Question: see any rust issues in the screws/holes after some months/years in the field?

I would like to add the idea of using electrical tape as a laid as friction tape to the inside of the rings. I have used his for a long time and the scope stays in place with a side benefit being no ring marks on the scope.

i use rosin too

excellent very clear and informative post by the op.Learned a few new things

thanks

Form, how's that Mini Grendel working out for you? Which model(barrel) is it? What are you using it for? What load(s) are you shooting in it?

I too use powdered rosin on ring to scope tube mating surfaces. A third advantage is it tends to prevent ring marks.

I don't recommend using electrical tape in there. It (or any other plastic + adhesive film) actually lubricates the joint under pressure, the opposite of increasing friction. You may not have had issues, but that's because there was still plenty of clamping friction for your use, not because electrical tape was a good idea.

I say that from the perspective of a fastener test engineer for a large company. One of the worst things I see in bolted joints is when someone forgets to remove tape or plastic film before bolting parts together.

If you feel the need to increase friction in the joint, use rosin or even Loctite, but not electrical tape.

In my experience the biggest issue with maintaining zero is the bedding of ones action. If bedded properly in a stable stock, there is no flexing of ones action with disassembly and reassembly for a thorough cleaning. Anything short of perfection in that realm and one will need a very scientific approach when it comes to torqueing action screws. If not so, then it's another session of chasing zero at the range when things are reassembled.

Do agree that proper scope installation is important too. Had a couple days of frustration years back when a windage screw in a Leupold mount came loose. Had me chasing a horizontal spread for about 15 rounds.

Not a tape advocate either, but I have used silicon seal with a heavy scope attached to a heavy kicker (30-378).


BigDave39355:
I don't care who you are. That there is funny!

I've been doing what Formidilosis listed, with the exception of nail polish on top of screws, for a long time. I think all of my rings have rusted screw heads. I'm assuming that it's accelerated by de-greasing everything but I'm hoping using nail polish as a final coat on top will minimize this rust......as is, I think the rust works well to help "lock" them ring screws in place so they don't loosen.

I used to do this but it left a big dent on one of my scopes, used 2 layers as a shim.

Use rubber cement on the inside of rings, if you want extra holding power.

Good info, learned a lot. Will be trying some of these methods. Thanks!

For 20 years I have used a film of clear GE silicone seal, applied with the index finger, between in the rings. The scope will absolutely not slip, even with minimum torque on the ring screws. after tightening the ring screws, and the silicone seal dries for a few minutes, you can clean any off the scope and edge of the rings with a rag without any residue remaining, it just rolls right off. When you remove the scope, you can remove the silicone seal from rings and scope with your finger. It minimizes any scratching of the scope tube due to misaligned rings. before using silicone seal, I used powdered rosin, but it is far too messy. That powder gets every where.Try silicone seal and you won't ever use anything else. RJ

Rubber cement works very much the same.

It did really well. A buddy shot his first mule deer with it and now he has it. Was the light/standard 20" barrel. Factory Hornady Black 123gr ELD-M is what I used. Elk, deer, bear, etc. there isn't anything in NA that I wouldn't use it on.






Yes. I like rust. Worlds best thread lock.

Bump for technical question:

If one chooses not to use loctite on their ring screws, is it best to install the screws dry or with a light coat of oil on them? Reason I ask is the torque values with dry screws vs loctite/oil will be different. If torquing dry screws, do you add a certain number of in/lbs to the wrench?

Thanks.

The scope-ring-base-receiver junctions are the greatest reasons for loss of zero IMO. Thorough Degreasing and Loc-tite are a priority all the way around and one can go even further with the bigger magnums by tapping the receiver for the bigger 8x40 screws and epoxying the bases and screws to the receiver.

In regard to fingernail polish, another way I use it (in a bright color) is to dab all the primers of my hunting loads with it, wiping off the excess with a cloth leaving a colored seal around the primer edges. It’s another barrier to moisture for cartridges dropped in the snow or even water and stuck back into a pocket or carrier.

I use clear polish.

Thanks for the great write-up. Now I'll think I have to re-mount all my scopes.