Scope Slip & Loctite on Mounts - S&B Scope w/ Spuhr Mount

Jul 13, 2013
286
4
18
The Woodlands, TX
#1
What are you using to prevent scope slip in your rings? Is there a rosin or glue I should be using? Need advice. I am running an S&B in a Spuhr on a .338LM.

Is anyone using loctite (blue) on their Spuhr ring screws to prevent them from backing out? How about using loctite on the rail screws?

Trying to make this thing bullet proof.
 

whatsupdoc

Duck season
Dec 12, 2017
179
76
28
Long Island NY
#6
If my memory serves me correctly Spuhr does not recomend using any adhesive on there mounts. they just state you can use it.
Always wondered why scope manufactures did not machine a positive stop on the scope.
 
Likes: Dthomas3523

Dthomas3523

Blind Squirrel
Jan 31, 2018
570
137
43
South Texas
#7
If my memory serves me correctly Spuhr does not recomend using any adhesive on there mounts. they just state you can use it.
Always wondered why scope manufactures did not machine a positive stop on the scope.
I believe you are correct. They "strongly recommend" rosin and list glue as an alternative what I'm assuming is a bomb proof setup.
 
Feb 13, 2017
1,859
795
113
Camano Island, Washington
#8
What are you using to prevent scope slip in your rings? Is there a rosin or glue I should be using? Need advice. I am running an S&B in a Spuhr on a .338LM.

Is anyone using loctite (blue) on their Spuhr ring screws to prevent them from backing out? How about using loctite on the rail screws?

Trying to make this thing bullet proof.
Are you actually having slippage problems ? If not, I would suggest staying with Spuhr’s standard mounting instructions. As shipped, their mounts have “wax” applied to the threads of the cap screws and all three of my SP 4006’s haven’t had any slippage problems whatsoever. Having said that, they are mounted on .223, 6x47 Lapua and 308 win, none of which are anywhere close to the recoil of .338L.

I have had, and tried many different ring/base combinations in the past and really never had any slippage problems, including Badger .50 cal rings on a .338L build. Really nice rings. My suggestion is that if you have a Spuhr mount, follow the mounting instructions, try it as is and if you have slippage problems, then and only then, try to solve the problem.

I have standardized on Spuhrs because they have thought things through to the N’th degree and their machining/finish/quality is just superb. By the same token, yes, there are many other really good mounts out there. It’s kind of hard to find a shitty scope mount these days.
 

pell1203

Full Member
Dec 27, 2007
885
49
28
Bellevue, WA
#10
I've heard of people painting a thin layer of clear nail polish enamel on the inside portion of the rings just prior to mounting the scope to prevent scope slippage. In theory, once dry, the nail polish will bind the rings to the scope tube. It comes apart easily when unmounting and a bit of nail polish remover cleans things right up.

I've never felt the need to try it, but have anecdotally heard it does work!
 

Crews

Sergeant
May 11, 2017
212
9
18
#11
I can certainly tell you that simply torquing everything to Spuhr's specs without anything else didn't work out well for me at all... 3/4 of the ring cap screws backed loose after 100 rounds of 6.5 Creedmoor.
 
Feb 16, 2017
133
8
18
34
Seattle / Montana
#14
I use a Spurh and S&B PMII on my 300 Win Mag. While not as bad as yours, I send the 215's at 3,000 fps. I have had no issues, and I do not use rosin. Blue Loctite at 15 inch pounds is all I do.
 
May 12, 2013
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18
#15
Just checked mine and they were loose. Going to snag some blue loctite today.

AI 6.5cm / S&B 5-25

Torqued with Borka precision torque limiters. I think approx 6 of them all together.
 

koshkin

Dark Lord Of Optics
Feb 22, 2006
1,131
327
83
Los Angeles
www.opticsthoughts.com
#23
If it slips, try some rosin powder. You really do not need much.

As far as blue loctite goes, I would strongly discourage using it on screws that hold the ring halves together. If you use a torque wrench and loctite, you are likely overtightening the screws. Wet torque and dry torque are different.

If the screws are loosening over time, degrease them.

That having been said, I have zero experience with Spuhr mounts. I have used a lot of other mounts and almost work more or less the same way. Mostly I use Aadmount and they do not slip on a 338LM in any way that I can see.

ILya
 
Nov 25, 2012
773
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28
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Southern NM
#24
Used rosin on a Spuhr 4601 mounting a PMII on a 338LM. Tongue all screws to spec & sequence. No issues after hundreds of rounds and occasionally, check screws with torque wrench. Not a fan of using Loctite on rings.
 
#25
I found this interesting and kinda makes sense as a possibility that I never thought of. My brother called vortex about a scope not tracking properly...their first question was do you use loctite on ring screws? They suggested the loctite would make the ring screws slippery and cause the torque wrench to read lighter and cause excessive torque pinching the scope tube causing it not to track properly. Basically they said if you use loctite use a lower inch pound. He hasn’t had a chance to experiment with it yet but pland to soon. Anyone have a similar experience and/or end result?
 
Apr 17, 2010
744
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Astoria, Or.
#27
Some thoughts on torque and ring scope installation. I talked to Kortik about torque values and he said they should be quoted based on dry parts. If parts are wet (oil, Loctite) reduce torque value by a quarter to a third. As to Spuhr specifically, I think they recommend the use of rosin.

Rosin, is available from Midway at twenty bucks for a half pound. Use of rosin for mounting scopes is pretty much standard in Europe but not so much here. You should also use rosin when using a barrel vice or blocks to remove a barrel. Some people recommend putting the rosin into suspension in alcohol and then painting it onto the surfaces you don't want to move. On my RPR I had to use a three foot cheater to get the barrel nut loose. The barrel never moved in the barrel vice. This stuff really works. If you remove the scope from the rings use alcohol to remove the rosin from the rings and scope tube. You will have no residue and no ringmarks. I apply the powdered rosin with a Q-tip. The halfpound will last you and all your friends about five lifetimes.


There is another consideration regarding the mounting of scopes. We use a significant numbers of rings that are aluminum with steel cap screws. I was told years ago to tighten to torque the screws in a crisscross pattern. Then to loosen and retorque each screw in a similar pattern. The reason given was that the first round would initially compress the aluminum threads and the second round would be more stable. I would love to hear from someone like Glen Seekins whether this is a wives tale or a worthwhile additional step.


Check with both the ring manufacturer and scope manufacturer for recommended torque. Use the lower.
 
Likes: tnbowhunter
Dec 12, 2017
179
76
28
Long Island NY
#29
Crap!! This thread jinxed me!!!! I just mounted a 34mm tube scope on a MPA mount and the thing slipped.

Got some rosin re-mounted it 40 rounds later it seems good. I use a little dot of latex paint between the front of the rear ring and the scope tube so if it moves I will know.

I quickly looked for torque specs for Steiner, S&B and Bushnell and none of the manuals appear to list an number.
 
Dec 12, 2017
179
76
28
Long Island NY
#30
How hard would it be for the scope manufactures to make the scope tube clamping area 1mm thicker and cut 1mm deep by 1mm wide spaced v notches in the tube, the scope rings would have matching notches and there would be no axial movement.