Spuhr ring marks

[MartyK2500]

I always taught that Spuhr would leave a scope mark free.
I had initially (2.5 years ago) installed my Vortex razor gen ll in a Spuhr, rings torqued to 25 in/lbs.

5-6 months and 600 rounds of .308 later, I uninstalled and reinstalled, as I had noticed my installation wasn't on par level wise (bubble level was straight and scope had a tiny amount of cant).
I took care to inspect scope at the same time, not one single mark no matter how faint.

Now fast forward and 2 years and another 2800 rounds of .308 later, I decided to buy another spuhr to put my scope in, since I changed scope to another rifle and do not have a handguard to clear anymore.
To my surprise, the finish on the razor looks smudged where the rings made contact,
No indentation or anything you can feel, but look wise you see the rings have affected the finish.
Almost as if the round count with the repeated recoil as an effect over time.

Now this scope I always said it will follow me to my grave,
But if ever I wish to buy a high end optics at some point, i'll have to research how to avoid this, as I see it as being detrimental to resell value of scope,

How has spuhr treated your scopes?

 

[scott_r]

Little character on your Vortex,,wont hurt anything. Use any of your equipment and its bound to get some cosmetic blemishes.

 

[Dmay]

It's a Vortex. I'm sure they warranty their paint forever and a day. Just take it in and they'll give you a new one every year.....

 

[MartyK2500]

I personally don't give a care for my vortex, my razor is a good working unit and all,
If my spuhr would do this to a high end scope i'd be pissed, tanks resale value....

 

[Longboat]

25 inch pounds is quite a bit over Vortex specs of 16-18 inch pounds. That's going to put a quite a bit more squeeze on the scope. No marks on my Razor torqued to 18 inch pounds. It has seen a lot of service on high recoil 338LM

 

[MartyK2500]

To be honest i just reviewed my Razors instruction manual and there was no mention anywhere.

Just reviewed Spuhr manual and says between 15-25 in/lbs, so i guess i could of went 20 to be in between.
Was always at 25 and for initial 600 rounds did not leave a single mark,
And now there’s no sharp mark or anything, just some finish colour smudge.

ARC rings have a torque spec of 55 in/lbs, i wonder what Vortex would have to say about that.

Anyways I’ll think it over if i uninstall and reinstall at 20,
At this point i am not sure I’d see the point of this exercise.

 

[the_blacksmith]

Torque specs on the rings from a scope manufacturer make assumptions; i.e.thread pitch, ring width, number of fasteners and tube diameter (to say nothing of misalignment or circularity). A ring set with higher/lower torque specs may have the same compressive force (PSI) on the scope tube once the pitch, ring width and tube diameter are accounted for. usually, of course, these parameters are similar, so they give an approximate torque value such as 16-18 in/lbs, but it may be that some permutations will give considerably more compression than expected. A common one would be if the thread pitch is 32 or 40, which can result in 125% (40/32) of expected compression, and once you compound the error of a 25mm tube vs 30mm (30x pi over 25x pi), you could be up to 150% (1.25 x 1.2) expected compression on a 1" tube, and THAT is only correct if the rings are the expected width.... the errors grow quickly with too many assumptions.

Hopefully the scope manufacturer doesn't miscalculate the tube diameter; I am meaning to show what can happen if you have a certain torque spec such as '25 in/lbs' and don't consider tube diameter. The torque applied to a screw on a 25mm tube will apply very different strain to a 34mm tube, all else equal.

My point being that since only the ring manufacturer has the data on the ring construction details they will probably give the best torque data, not the scope manufacturer as they have no idea what sort of rings you will use. Of course, the scope maker knows how much compressive load the tube can handle and the ring manufacturer doesn't, so you have to make assumptions at some point. Consensus does seem to be that vortex scope tubes are much more prone to fail from ring tension than most other manufacturers, however.