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

Jul 13, 2013
341
10
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
391
235
43
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
2,119
849
113
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
3,676
4,035
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
1,034
159
63
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!
 
Likes: LG65CM

Crews

Sergeant
May 11, 2017
479
92
28
#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
153
15
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
376
46
28
#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.
 

2bits

. . . . . . .
May 18, 2014
29
3
3
Washington State
#17
I push the scope forward in the rings until the turret housing stops against the front ring. Yup, it’s that simple.
That shouldn't be necessary to prevent slippage and gives your objective bell the minimum support. I personally do the opposite - put the front ring as close to the bell as your rail and eye relief permits.
 
Likes: shoobe01

bjay

Private
Oct 19, 2009
3,689
251
83
Aloha state HI
#20
Scope actually pushed forward from recoil..mine did the same shooting 300nm
I tightened it to 25 inch it was 17"(no locktite) will see if it work.if it still slip.ill replace rings with ARC Resized_20180206_084623.jpeg
 

koshkin

Dark Lord Of Optics
Feb 22, 2006
1,608
962
113
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
859
121
43
63
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.
 
Feb 18, 2012
110
25
28
Middle Tennessee
#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
870
100
43
71
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.
 

whatsupdoc

Duck season
Dec 12, 2017
391
235
43
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.
 

whatsupdoc

Duck season
Dec 12, 2017
391
235
43
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.
 
Aug 31, 2017
141
25
28
Austin Texas
#33
like Afkirby said the Spuhr mounts come waxed on the mounting screws so you dont need to do anything to them other than torque them. I think what may be the problem is because these mounts last forever they get resold and screwed/unscrewed and cleaned so many times the wax is gone. I have two spuhr mounts and havent had any issues (one is on a 28 nosler, but with a nice muzzle device) so not a ton of recoil but still no issue. I just make sure to check the mounting screws with my torque wrench every time I clean it and havent had any issues.
 

FCrifles

formerly eddief
Feb 22, 2013
181
10
18
Mi
www.fosnaughcustoms.com
#34
Rosin works great. There is purple loctite that i have used on ring cap screws before for customers that had to have something. Degrease your screws and the rings. I always use blue on the base screws.

All my personal scopes get reference marks with a pencil on front and back of scope tube right up against the ring on the top half. This will at a glance show you if your tube is slipping fore and aft. Then with a silver or gold sharpie I dot the ring cap and scope tube. This will show rotation at a glance.

These marks are the first thing I check if the rifle shows a problem.
 

scudzuki

Gunny Sergeant
Jul 1, 2012
2,069
85
48
53
Philadelphia suburbs
#35
I just checked 2 of my rifles, one with a Spuhr 4006 mount and the other with Seekins 6/4 screw low 34mm rings, both gripping Minox ZP5 5-25 scopes.
Hundreds of rounds under the Spuhr mount and roughly 150 under the Seekins rings.
I assemble with clean and dry scope tube and rings/mount clean and dry screws and tapped holes.
No scope slip, screws have not loosened at all.
I've never had a scope move or screws loosen on a quality scope mount (or rings) when assembled clean and dry and properly torqued.
Anecdotal not scientific, but I'll continue to assemble as I've always done.
 
Likes: Nemain
Jan 5, 2010
2,416
91
48
32
SE Georgia
#36
I wonder how many people clean their mounts before installing stuff, it's amazing how much gunk is piled in the threads of new mounts. I've not had any scopes slip, screws back out, or anything loosen with SPUHR, Seekins, Nightforce, Badger, or any other quality mount that was degreased and correctly installed. Oh, make sure theres no oil on your scope tube either.
 
Mar 24, 2018
342
59
28
AZ
#37
I wonder how many people clean their mounts before installing stuff, it's amazing how much gunk is piled in the threads of new mounts. I've not had any scopes slip, screws back out, or anything loosen with SPUHR, Seekins, Nightforce, Badger, or any other quality mount that was degreased and correctly installed. Oh, make sure theres no oil on your scope tube either.
This has already been explained by Spuhr himself to be incorrect. Keep the oil on your Spuhrs so that you wet torque. Not to be confused with wet twerk.
 

BigJimFish

Full Member
Jul 24, 2011
582
24
18
37
Columbus, OH
#41
The rosin strikes me as a pretty good idea though I have never tried it or had a scope slipping problem. I may try it in the future though to see if it lessens any marks left by rings on scope finishes.

I think locktight is a terrible thing because I think it makes the load you are applying to the screws inconsistent relative to the torque applied especially after the first application.

I have always run a dry and clean scope and rings with greased cap screws. For most scopes these have been torqued @20 inch lbs though this ammount can vary by scope or even by the configuration of the ring cap screws.