Rifle Scopes Tangent Theta Ring Torque

[Kegjohn]

Recently purchased TT 5-25x56 and was reading the manual and noticed it said max torque on ring caps 15 in lbs. I was wanting to use this scope on 338 lapua and this seemed really low for torque as my nightforces are torqued at 25 in lbs. So any advice from the guys running tangent thetas would be great. Thanks in advance

 

[Lil Casino]

In a Spuhr mount I use 15in lbs on mine with blue Loctite and 0 issues, but not shooting 338 either.

ETA: ARC M10 if you're really that concerned

 

[HousePlant]

Try 15. If it moves, deal with it later.

 

[oldfatguy]

Try 15. If it moves, deal with it later.

S&B suggests rosin powder.

OFG

 

[DairyDictator]

Vortex does the same on their razor line.

The amount of force even 15 in-lbs put on a scope tube is insane. Just running through the bolt force formula with a #8 bolt is somewhere along the lines of 500lbs of force per bolt. So about 2000 lbs of force per ring, assuming the formula I'm using is correct and assuming the rings have 4 screws per cap. This would explain why ARC wants their scope clamps torqued to 55 in-lbs, as they only have 1 bolt up top.

If it slips, Rosin is usually recommended

 

[Bkultra]

TT updated the max to 25 in lbs, see https://www.snipershide.com/shootin...ged-torque-spec-response-from-ati-tt.6915154/

That being said I have always used 15 in lbs, even with my 300NM, without a problem (era tac mount). People have reported problems with binding the parallax when using more than 15 in lbs in sphur mounts.

 

[Kegjohn]

Thanks for all the responses. I had seen a claim that they had changed it to 25in lbs on another forum but I couldn’t find any proof to back that up. Now I know that’s correct.

 

[samb300]

There are a couple of threads out there documenting a *potential* issue with the TT optic and Spuhr mounts. Some users have multiple TT's and have never had an issue, others like myself had an issue right out of the box. At 15 in-lb the Spuhr front ring would cause the parallax knob/mechanism to bind.

I cannot comment on whether or not 15 in-lb will be sufficient to withstand 338LM recoil. All I will say is if you use a Spuhr and get any parallax binding, try another ring like ARC, NF, or Badger and that might solve the problem.

 

[hk dave]

I run a TT 5-25 on a Spuhr at 15-18lbs, shooting 338lm. I haven’t noticed any issues.

 

[chrome]

Quick gut check on this:

TT 5-25x in an ARC QD Mount. ARC recommends 55in lbs given their design, that is still ok w/TT?

 

[DairyDictator]

Quick gut check on this:

TT 5-25x in an ARC QD Mount. ARC recommends 55in lbs given their design, that is still ok w/TT?

Just based on some quick math, yes. ARC rings have an odd design where the screws don't put near as much direct force on the optic as regular split rings.

But when you dropped 3k or so on an optic.... might wanna check with the people who decide whether or not to honor the warranty rather than trust a stranger on the internet.