Rifle Scopes Scopes Slipping

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dakor

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Minuteman
Feb 8, 2007
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#1
I am having an issue with two different scopes with 30mm tubes made by the same manufacture that will not hold on a two different rifles. One rifle is a 338 Edge with a brake and the other is a 375 RUM with a brake. The setup for the optics starts with EGW Picatinny rails on both rifles. The rings I have tried are Burris tactical, Vortex tactical (I think these are the same rings as the Burris) and Burris Zee rings. These scopes are not cheap either and this is supposed to be a high level optic manufacture.


I started with the manufactures 20 inch lbs of torque recommendation and I am now at 40 inch lbs and still no dice. I have used brake cleaner on the scope tubes and rings to make sure no oil residue or anything like that could be causing the slipping. The rings have been lapped. I have measured both scope tubes and they are 30mm I am thinking it is something in the paint on the tube causing the issue. Manufacture is not helping at this point and does not seem to want to help the situation. Recoil on the edge is about like a 300 wsm a Tikka T3 lite with no brake and the recoil on the 375 rum is about like a 8lbs 300win without a brake. Any suggestions on how to fix this?
 
#3
I think you may have lapped the rings too much. You only need to use the lapping tool slightly to get rid of rough spots. If you use it to completly remove material the rings won't grip the scope tube.
Try this take a thin rubber glove a exam type glove cut the thumb off and the other end on the part and slip it each thuimb part over to the tube both sides. Place in rings and torque down to required specs. and trim excess glove material off of. It should hold well also if possible get some rosin and place in scope ring channel should prevent scope movement.
If not get a set of good rings and don't lap and see what happens.
 
#4
I agree, get rid of those Chinese rings and use quality like Seekins, Leupold Mark IV, Badger etc. And 40 inch lbs is WAY too much on a scope tube. I have never had one slip with a maximum of 15 in-lbs using quality rings.
 
#5
The rings are not over lapped they have the paint on in places still. Do you gentleman have any recommendations on a set of rings? Missed your post I know 40inch lbs was too much I wanted to see if they would hold and they wont. I am going to get a set of Mark 4 rings for both rifles. Thank you gentleman.
 
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#6
I like and use Leupold Mark 4 rings. I have both steel and aluminum versions and have never had an issue with any. Personally, I like the 1/2" nut attachment versus 2 smaller screws.
 
#9
Seekins and throw away the lapping bar.<script type="text/javascript" src="safari-extension://com.ebay.safari.myebaymanager-QYHMMGCMJR/e43f3fd0/background/helpers/prefilterHelper.js"></script>
 
#11
The Burris rings I used are solid steel and these do no use the inserts like their Signature Rings. The most interesting part is these Burris rings were on that 375 Ultra for almost two years with another scope and it never moved after a couple hundred rounds fired. Now I buy a new scope and I take the old scope off and put the new scope on and after 5 rounds the scope moves WTF? The 338 Edge had a temporary scope on it using Burris rings and it never moved and now after the scope swap it moves? So I tried the tactical rings as stated and both scopes still move? If the Mark 4 rings fail to hold then my suspicion is right that it is the scopes. I have used the Burris Zee Rings for years on some big stuff and never had a scope slip. My 375 H&H wears them and weighs 9lbs ready to go with no brake on it and has hundreds of rounds down it the Burris Zee rings on there have never failed.
 
#13
For my 300WM, I had to use this trick to stop slipping once and for all. I placed on the inside of the rings, baseball bat's handle friction black tape. You get one at any Sports Academy.
 
#16
MJY65 said:
Seekins and throw away the lapping bar.<script type="text/javascript" src="safari-extension://com.ebay.safari.myebaymanager-QYHMMGCMJR/e43f3fd0/background/helpers/prefilterHelper.js"></script>
Click to expand...

BINGO!!! A HUGE +1 to the above!! Seekins... the very best around. Nothing but Seekins will ever touch my scope... PERIOD!!

DK
 
#18
LawnMM said:
Stop lapping rings. Buy quality rings that don't need lapping. Your problems will solve themselves.
Click to expand...

Definitely! Lapping is a holdover from the cheap stamped steel rings of several decades ago. Those rings were rarely straight and would gouge the crap out of a scope. They were made with HUGE gaps along the side, so you could tighten the heck out of them. Modern CNC machined rings have no such gap. As soon as you remove a bit too much material from the inside, the sides will make contact and will get no tighter on the tube. You could shear the screws off and not get it any tighter. If you purchase a quality ring like Seekins (or others in that price range) there is absolutely nothing you can do with a lapping bar and abrasive that will improve on the accuracy of its fit. You are only egging out the hole and making everything looser.<script type="text/javascript" src="safari-extension://com.ebay.safari.myebaymanager-QYHMMGCMJR/e43f3fd0/background/helpers/prefilterHelper.js"></script>
 
#19
MJY65 said:
Definitely! Lapping is a holdover from the cheap stamped steel rings of several decades ago. Those rings were rarely straight and would gouge the crap out of a scope. They were made with HUGE gaps along the side, so you could tighten the heck out of them. Modern CNC machined rings have no such gap. As soon as you remove a bit too much material from the inside, the sides will make contact and will get no tighter on the tube. You could shear the screws off and not get it any tighter. If you purchase a quality ring like Seekins (or others in that price range) there is absolutely nothing you can do with a lapping bar and abrasive that will improve on the accuracy of its fit. You are only egging out the hole and making everything looser.<script type="text/javascript" src="safari-extension://com.ebay.safari.myebaymanager-QYHMMGCMJR/e43f3fd0/background/helpers/prefilterHelper.js"></script>
Click to expand...
+1
Lapping bars are old school...you can lap a old lapping bar with the trueness of modern CC machine products.
 
#22
oldfatguy said:
So what brand scope did you mount that slipped after 5 rounds?

OFG
Click to expand...

I do not want to open that can of worms at this point so I am keeping that to myself as of right now. Last night I took a new set of Burris Tactical rings that are not lapped and put them on the 375 Ultra. I started at 20 inch lbs and finally at 45 inch lbs they seem to be holding. Yes I know this is too tight but I wanted to see what it would take for them to hold. My Mark 4 rings should be here tomorrow or Thursday so I should have some results by the end of the week.
 
#24
If it doesn't break anything, it's not too tight. The specs for scope rings are pretty conservative if you ask me (probably to keep people from breaking stuff - that's what I'd say if I made scope rings). On hard kicking magnums, I don't see the harm in torquing them up a bit more if you know what you're doing.
 
#25
I have some rosin for taking rifle barrels off but I really do not want to take that route if I can avoid it. Back in the day no one ever used inch lbs wrench's you tightened the ring screws until you could not tighten them anymore and it was good. :D
 
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#27
dakor said:
I have some rosin for taking rifle barrels off but I really do not want to take that route if I can avoid it. Back in the day no one ever used inch lbs wrench's you tightened the ring screws until you could not tighten them anymore and it was good. :D
Click to expand...

Assumeing that tape and locktite are also something you would prefer to avoid then you will have to use better rings. Have you read Big Jim Fish's article on the American Rifle Company rings? Sniper's Hide » BigJimFish Review of American Rifle Company M10 QD-L Scope Mount
 
#29
Don't forget to degrease both the scope rings and the scope tube. I know that all four sets of Mark 4 rings I own, steel and aluminum, came coated in protective oil. Like I said, I use 15 in-lbs and have never had an issue. I don't think you'd need more than 20 in lbs to hold even on hard kicking calibers.
 
#30
dakor said:
I do not want to open that can of worms at this point so I am keeping that to myself as of right now. Last night I took a new set of Burris Tactical rings that are not lapped and put them on the 375 Ultra. I started at 20 inch lbs and finally at 45 inch lbs they seem to be holding. Yes I know this is too tight but I wanted to see what it would take for them to hold. My Mark 4 rings should be here tomorrow or Thursday so I should have some results by the end of the week.
Click to expand...

If you are torquing the ring screws to 40 in. lb and your scope is still slipping there is something seriously wrong in the system. Have 2 PMII 5-25 x 56 scopes in Badger rings. Both torqued to ~18 in. lb. on a 308 and 260 with about 1500 rounds fired from each. Neither had ever moved, not even a little bit. The MK 4 6.5-20 x 50 in TPS rings hasn't moved either.

OFG
 
#31
You are shooting a 260 and 308 those do not have much recoil. The 338 edge and 375 rum weigh 10.5 lbs ready to go and even with a brake have about 3 times the recoil of a 260 or 308. That said my Leupold never moved on my 375 rum for the two years it was on there using Burris Zee rings even after I shot it for the first month after I built it without a brake it never moved and that was 85+ lbs of recoil each time the trigger was pulled. I bought a new scope because I wanted to go from MOA to MRAD and the only thing that has changed on the 375 is the scope and it slips until you crank the piss out of it. The edge is newer I just built it a few months ago but it to had another scope on it that is a temporary scope and it never moved but now the new scope moves even when you tighten the piss out of it the scope still moves. So if you think about it logically the only thing that has changed on the two rifles were the scopes and they slip the old scopes do not slip so to me if the rings on both rifles can hold scope x but scope y does not hold and you try two other sets of rings and then only one of the new scopes will hold after being tightened to 45 inch lbs the other at 45 inch lbs still does not hold it has to be something with the scopes.
 
#32
I don't agree at all with lapping.
The quality of the rings says NOTHING if lapping is needed or not, but the picatinny rail does.
If the rail not is straight (and mostly are not) then the rings needs to be lapped.

The recoil of the meantioned calibers are pretty tough, and I strongly recomend using rosin.
Rosin does also saves the scope as there is a tiny layer betwen scope and rings.
 
#34
First, if your 338 edge kicks as hard as a wsm tikka.........get a better brake.
I have a wsm tikka and three 338 edge rifles ranging from 13-16lb waring Ross brakes and none of them have FELT recoil even worth mentioning.........................however, Having bean in your shoes: Burris with inserts=Forget it..... Rosin, lock tight, brake cleaner, leupold $$$, lapping/no lapping, all these fine folks that have never had a problem, yada yada yada....... tried it all, lot of waisted ammo to prove it.
Solution for me: 4 =yes= FOUR, six hole cheap weaver picatinny tactical rings 25"lb on the caps.
NEVER a hiccup, hesitation or doubt since.............:)
 
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#35
LawnMM said:
Stop lapping rings. Buy quality rings that don't need lapping. Your problems will solve themselves.
Click to expand...
I agree that the way rings are machined on CNC machines produces precision matched pairs of rings. But to just say don't ever lap them overlooks some other possible problems. What if the Picatinney rail you bought is slightly crooked, or the base holes in the action are not in line with one another? You could easily end up with two precision made rings that are each centered along a different axis. I'm just saying you could make a case for lapping a set of rings.
 
#36
Magnumdood said:
I agree that the way rings are machined on CNC machines produces precision matched pairs of rings. But to just say don't ever lap them overlooks some other possible problems. What if the Picatinney rail you bought is slightly crooked, or the base holes in the action are not in line with one another? You could easily end up with two precision made rings that are each centered along a different axis. I'm just saying you could make a case for lapping a set of rings.
Click to expand...

No, you'd make a case for buying a quality CNC machined scope base. Or having your action trued up. If the holes weren't aligned the whole base would be off axis and lapping the rings wouldn't fix anything. If the base itself was THAT crooked why would you deliberately lap a set of rings and take them OUT of concentric alignment to fix a problem created by a shit scope base? Buy a better scope base. This is one of those things that you either figure out early on by listening to others or you learn the hard way yourself over time. Don't spend 1000-3000 bucks on a scope and then say that a 120 dollar scope base or a 150 dollar set of rings is too expensive. You want cheap you're going to get cheap tolerances and cheap manufacturing. This is a game of inches and reducing the number of those inches isn't cheap. What's cheaper in the long run? Buying cheap shit and having to buy quality stuff anyway or just buying quality components from the get go?
 
#37
Lawn

If you look closely on many picrails they are not true.
And even if they are, when they are attached to the Handgrinded Remington action they become bent.
Take any set of you'r favourite rings and mount it to a rail and just mark over with a lapping bar and you will find out that the lappingbar marks uneven in the rings.

If you don't lap it after you realized it's not straight you will mount you'r scope in a tension and if you lap it you will mount you'r scope without tension.
 
#39
Spuhr said:
Lawn

If you look closely on many picrails they are not true.
And even if they are, when they are attached to the Handgrinded Remington action they become bent.
Take any set of you'r favourite rings and mount it to a rail and just mark over with a lapping bar and you will find out that the lappingbar marks uneven in the rings.

If you don't lap it after you realized it's not straight you will mount you'r scope in a tension and if you lap it you will mount you'r scope without tension.
Click to expand...

Again, I don't think that's a reason to lap rings. That's a reason to buy a better base, or to have somebody put an action bar on your Remington, open up the base holes, and true everything up. I buy your mounts, Hakan, because they're machined beautifully. I don't throw your mount on a 30 dollar scope base. I buy something that's been machined by Seekins, Nightforce, Badger, etc. I've had my scope base holes opened up and aligned, they're as straight as they're going to get. If they were off, I wouldn't lap a Spuhr mount, and I wouldn't lap a set of 150 dollar Nightforce rings, because my cheap shit scope base wasn't true. See what I'm saying?
 
#40
I carefully line the rings with electrical tape. It keeps marks off the tube and offers some grip between the surfaces. Also I use a sharp pencil to mark the scope location.
 
#41
Spuhr said:
I don't agree at all with lapping.
The quality of the rings says NOTHING if lapping is needed or not, but the picatinny rail does.
If the rail not is straight (and mostly are not) then the rings needs to be lapped.

The recoil of the meantioned calibers are pretty tough, and I strongly recomend using rosin.
Rosin does also saves the scope as there is a tiny layer betwen scope and rings.
Click to expand...

Wouldn't this also make a strong argument for employing a one-piece mount (like the ones you make), rather than individual rings?

To me it seems like running a well made one-piece scope mount would eliminate some of the issues that cause people to have to lap their rings in the first place (ex: the rails not being precisely machined). But, you're the expert here, not me! For whatever it's worth, I run one of your mounts on my Tikka, and another one on my AIAX. They're VERY solid.

I see lapping as a solution to a problem that shouldn't really exist in the first place (in a perfect world, with modern manufacturing techniques). Maybe I'm not skilled enough as a craftsman, but lapping seems like it would be a less precise solution when compared with the idea of buying a very high-quality one piece mount in the first place. I will say that I removed my Schmidt and Bender from one of your Spuhr mounts to place it in another one of your mounts, after giving it a couple of years of hard use in the first mount. The scope (which was not mounted with rosin) looked perfectly new when I pulled it from the first mount, without the slightest hint of a mark from your mount.
 
#43
Spuhr said:
If you look closely on many picrails they are not true.
And even if they are, when they are attached to the Handgrinded Remington action they become bent.
Click to expand...

I recognize your expertise and fine products so I have a hard time arguing with you. But I will. I've mounted six or seven pic rails on bolt guns in the last year and all of the picatinny rails (including ones from EGW, Warne, TPS, and Ken Farrell) appear to be straight and true to my naked eye when viewed along the top or the edges. Several of them were also checked with quality (albeit woodworking market quality) steel rulers and were still straight along the top surface. I don't have a granite table and the ability to measure 1/100,000 of an inch, but they were true to the limits of the techniques I mention. I have also found it quite easy to spot a bent pic rail both visually and with a steel ruler, and have found most non-bedded separate rails are not straight and flat, even if mounted at a good factory (the FNAR I owned is one example - everything factory FNH-USA, the front 2" of the rail was quite significantly bent, to the point that scope mounting over that portion was a problem).

Now, the highlighted part - in my experience this is the big, and ever-present issue. No matter what combination of seemingly high quality pic rail (and I think Farrell are pretty good) and receiver (Howa 1500 are reputed to be well made, and on the barely machined late-model Savage tubular receivers you would hope that the steel tube is straight), there is a gap between rail bottom and receiver top at one end or the other, which is easily fixed with bedding. With that little chore done, the mounted rail is still straight as far as I can see.

I realize nothing is truly straight if you measure in small enough units. I guess my question is, at what level of straightness does it no longer matter? And are you seeing misalignments that really matter when combining a quality aftermarket picatinny rail with bedding onto the receiver?
 
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#46
LawnMM said:
Did you lap them?
Click to expand...

No I didn't lap them. Just examined them to make sure there were no rough spots, there weren't any and installed them My brother had ordered them for his SPS but they were to high so I got them from him. He ordered the correct size for his SPS 308 an hasn't had any problems with the unlaped rings slipping either. They were also torqued to 18 inch pounds.
 
#47
samnev said:
No I didn't lap them. Just examined them to make sure there were no rough spots, there weren't any and installed them My brother had ordered them for his SPS but they were to high so I got them from him. He ordered the correct size for his SPS 308 an hasn't had any problems with the unlaped rings slipping either. They were also torqued to 18 inch pounds.
Click to expand...

I didn't think you had, that was a question for the benefit of others. The point is, we all need to stop lapping rings, if anyone is THAT concerned about alignment, buy higher quality stuff, don't take a set of rings set up for what? .004 pinch fit and turn it into a .001 slip fit
 
#48
D.ID said:
First, if your 338 edge kicks as hard as a wsm tikka.........get a better brake.
I have a wsm tikka and three 338 edge rifles ranging from 13-16lb waring Ross brakes and none of them have FELT recoil even worth mentioning.........................however, Having bean in your shoes: Burris with inserts=Forget it..... Rosin, lock tight, brake cleaner, leupold $$$, lapping/no lapping, all these fine folks that have never had a problem, yada yada yada....... tried it all, lot of waisted ammo to prove it.
Solution for me: 4 =yes= FOUR, six hole cheap weaver picatinny tactical rings 25"lb on the caps.
NEVER a hiccup, hesitation or doubt since.............:)
Click to expand...

I appreciate the input on the scopes as for the brakes If you are running a 13lbs and 16 lbs rifle you would have a lot less recoil then these rifles. I built the rifles for high country backpack Elk hunting so they are light weight mountain type rifles that can still shoot long range and be very accurate. The 338 edge weighs 7lbs 2 oz bare rifle and the 375 rum weighs 6lbs 14 oz bare rifle. With the scope, bipod, sling, and 9 shells on the stock both are in the 10.5 to 11lbs range. That 2 to 5 more lbs of gun makes a huge difference in recoil so you are not going to have as much recoil.
 
#49
If its a fit issue with the rings being a few thousandths oversized, take off the top half of the ring and place it on a sheet of 600 grit sandpaper and gently rotate. You should be sanding the underside of the screw hole of the top half.

The idea is taking a few thousandths off the bottom half of the top ring will reduce the radius thereby shrinking the rings.
 
#50
A. Start with good rings like Seekins or ARC (or Badger or Leupy Mark IV, you get the idea)
B. Install at least one of the rings as close as it can get (without damaging the scope tube; the chamfer on the inside of the rings is often smaller than the radius where the scope main tube meets the turret housing and ocular housing) to the ocular housing (rear ring) or where the turret housing (front). Torque to the ring manufacturer's recommendation (20 inch/lbs. for Seekins, 50-55 inch/lbs. for the ARC).

The scope then cannot slide forward any farther.
 
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