TT315H or M with ARC M-Brace users.

H

HunterBrett

Private
Minuteman
Aug 3, 2024
6
1
Wisconsin
#1
Hi all!

New here and happy to be here.

I have a question for anyone that has a Tangent Theta 315H or M that use or have used ARC M-Brace rings. My question or concern is the torque specs of the ARC rings at 55in-lbs.

I have read multiple discussions of why ARC torque specs are what they are along with myself having a few sets " hence the question " while using them with other optics with zero issues. This is the first optic I have purchased in this price range and the last thing I want to do is damage it in anyway as Tangent Theta's torque specs indicate no more than 15 in.lbs

So, if anyone who has or had used this combo had issues at all approaching ARC's recommended torque specs.? I suppose I could just start at 15in-lbs and work up from there or just get different rings and be done with it.

Thanks!
 
#3
I should have mentioned I did reach out to TT and this was their response.

" The rings are fine to use, but do not use their suggested torque spec.

The TT315H can withstand 15 inch lbs, anything more than that and you risk crushing the tube. If the rings are well made, you shouldn’t require more than that anyway. Their suggested spec is just what the rings will handle, but the scope will not take that.

If you find it’s loose in the rings, you can slowly adjust to 20, but that would be max. You will notice binding in the parallax adjustment first, and then the tube will get crushed after that.

Regards, "


I suppose I can reach out to ARC but after reading multiple threads regarding their torque specs they claim it is safe because of their design. That is why I was hoping to get feedback from users who may have or have this combo to see if they had any issues.
 
#4
HunterBrett said:
I should have mentioned I did reach out to TT and this was their response.

" The rings are fine to use, but do not use their suggested torque spec.

The TT315H can withstand 15 inch lbs, anything more than that and you risk crushing the tube. If the rings are well made, you shouldn’t require more than that anyway. Their suggested spec is just what the rings will handle, but the scope will not take that.

If you find it’s loose in the rings, you can slowly adjust to 20, but that would be max. You will notice binding in the parallax adjustment first, and then the tube will get crushed after that.

Regards, "


I suppose I can reach out to ARC but after reading multiple threads regarding their torque specs they claim it is safe because of their design. That is why I was hoping to get feedback from users who may have or have this combo to see if they had any issues.
Click to expand...
Whomever answered your email at TT doesn’t seem to understand Arc rings.

My guess is that 55 in/lbs on Arc rings approximates somewhere around 18-20 in/lbs “4-to-6 screw regular ring” torque. If it didn’t Arc rings would crush scopes left and right. I own multiple sets of Arc rings and one-piece mounts, btw.

20 in/lbs with Arc rings would probably lead to a slip-fest, with your scope sliding around during shooting. Not good for the scope’s finish.

I could see Ted from ARC or TT suggest a lower number than 55 for a crush-prone/lightly built scope, but 20? Wow.

I think ZCO suggests 35 in/lbs for ARC rings after some of their scopes had some microscopic defect on the end of a lens or lens interface. This resulted in a certain lens element cracking.

All of the above is my guessing and my recollection of previous web posts. Do your own research to confirm.
 
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#5
carbonbased said:
Whomever answered your email at TT doesn’t seem to understand Arc rings.

My guess is that 55 in/lbs on Arc rings approximates somewhere around 18-20 in/lbs “4-to-6 screw regular ring” torque. If it didn’t Arc rings would crush scopes left and right. I own multiple sets of Arc rings and one-piece mounts, btw.

20 in/lbs with Arc rings would probably lead to a slip-fest, with your scope sliding around during shooting. Not good for the scope’s finish.

I could see Ted from ARC or TT suggest a lower number than 55 for a crush-prone/lightly built scope, but 20? Wow.

I think ZCO suggests 35 in/lbs for ARC rings after some of their scopes had some microscopic defect on the end of a lens or lens interface. This resulted in a certain lens element cracking.

All of the above is my guessing and my recollection of previous web posts. Do your own research to confirm.
Click to expand...
I appreciate your reply. The last thing I want is the " slip-fest " like you mentioned and from my reading I believe 20 in-lbs would be way to low. Was hoping someone with this combo could chime in, maybe even will. I guess I could always throw on my set of Seekins rings and be done with it but was hoping to use the Arc's.
 
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#9
HunterBrett said:
I should have mentioned I did reach out to TT and this was their response.

" The rings are fine to use, but do not use their suggested torque spec.

The TT315H can withstand 15 inch lbs, anything more than that and you risk crushing the tube. If the rings are well made, you shouldn’t require more than that anyway. Their suggested spec is just what the rings will handle, but the scope will not take that.

If you find it’s loose in the rings, you can slowly adjust to 20, but that would be max. You will notice binding in the parallax adjustment first, and then the tube will get crushed after that.

Regards, "


I suppose I can reach out to ARC but after reading multiple threads regarding their torque specs they claim it is safe because of their design. That is why I was hoping to get feedback from users who may have or have this combo to see if they had any issues.
Click to expand...

Yeah they do not know anything about ARC rings. If you damage the TT scope with the 55 in/lbs recommended by ARC then the scope is a POS as I have much less expensive scopes in the M Brace mounts and no issues at 55in/lbs.
 
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#10
carbonbased said:
Whomever answered your email at TT doesn’t seem to understand Arc rings.
Click to expand...
This ^^. Ted is an engineer's engineer and he has absolutely done the work to determine equivalent torque for his one screw unique design versus the typical multi-screw top ring on pretty much all other rings.

I use ARC rings and LOVE them.

carbonbased said:
I think ZCO suggests 35 in/lbs for ARC rings after some of their scopes had some microscopic defect on the end of a lens or lens interface. This resulted in a certain lens element cracking.
Click to expand...

What I remember was one guy....who was a real piece of fucking work...had a cracked lens...parallax lens maybe...with his ZCO and ARC rings? I do not remember ZCO saying there was a defect on the edge of the lens but it was a long and contentious thread, mostly due to the OP.

If I remember correctly, ZCO suggested 45 in/lbs.

When I first mounted a 5-27 in ARC rings I went straight to 55 in/lbs and had a bit of drag on the parallax adjustment so I quickly backed off and then brought them up to 55 in/lbs incrementally (25, 45, then 55) and had zero problem.

The scope has been remounted a couple of times and I've been just using 45"/lbs since and don't seem to have any issue with slippage with 6.5 CM at that torque and the parallax is runs free and with out drag.

I'm pretty positive I could increment them back up to 55 from 45 without issue but it doesn't seem necessary. Perhaps with a magnum I would consider going to 55.

Now, I also don't put my rings right up against the turret bell. Doing so may cause problems on its own, right?
 
#11
I have a TT315M, and spoke with TT about their torque requirement as well (years ago). The person I spoke with had zero clue how to get from screw torque to stress imparted on tube.

Also for what it’s worth, I’ve used 18 in-lb on a lightweight magnum hunting rifle with no issues, and 15 in-lbs on a medium/lightweight 6.5CM with no issues.
 
#14
Thanks to all for your replies!

I hopefully did not make it sound like I was debating the torque specs advertised by Arc themselves because that was not the case. Just looking for info if there were any users who have, or had used this combo. I read a thread where users using Spur mounts at their recommended specs 15 or 20 in-lbs. Cannot remember if it was 15 or 20, but some were having issues with the parallax binding up bad and some scopes being ruined.

I guess I could always torque up slowly until I feel some binding if any of the parallax and back down if I do.
 
#21
I'm a multiple Tangent owner, former multiple ZCO owner, and former ARC MBrace owner... I went through this multiple times, talking back and forth with all 3 of the above due to several issues.

At the end of the day, the issue was the MBrace (yes, I brought it up with ARC). I got rid of the MBrace and all my problems went away. ZCO didn't even recommend them at the time.

Spuhr may have issues with their clamps. But I'll take a broken clamp over a crushed tube or binding parallax any day of the week... The former is more obvious and easily fixed.

My next mounts will likely be GrayOps.
 
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#22
NiteQwill said:
I'm a multiple Tangent owner, former multiple ZCO owner, and former ARC MBrace owner... I went through this multiple times, talking back and forth with all 3 of the above due to several issues.

At the end of the day, the issue was the MBrace (yes, I brought it up with ARC). I got rid of the MBrace and all my problems went away. ZCO didn't even recommend them at the time.

Spuhr may have issues with their clamps. But I'll take a broken clamp over a crushed tube or binding parallax any day of the week... The former is more obvious and easily fixed.

My next mounts will likely be GrayOps.
Click to expand...
Was the issue that the M-brace was defective or that the torque spec was not appropriate or tolerated by the scope?
 
#24
NiteQwill said:
Torque spec was not tolerated by the scope. The 36mm MBrace was exchanged for another one, which had the same issue.
Click to expand...
I wonder if some relatively unque ZCO internals were at play here, coupled with perhaps some unique pressure from the Mbrace?

I did some digging:

ZCO ok with 55 in/lbs in 2019; CSTactical likes ARC in 2024
www.snipershide.com

Rifle Scopes - ARC ring torque with ZCO?

Need some help on what to torque my ZCO in ARC rings. ARC recommends 50-55 in/lbs of torque and ZCO recommends not to exceed 25in/lbs. Is 50-55 safe to use on the ZCO tube? Just don’t want to take a chance in damaging a brand new scope.
www.snipershide.com www.snipershide.com

ZCO lens cracking issue (I did some image sleuthing in that one)
www.snipershide.com

Top scope brand that costs 4k+ keeps cracking

About 3 months ago I bought top of the line scope. (I don’t want to use the manufactures name because they’ve been great). I mounted it on my 6.5 creedmoor with ARC m-brave mount, torqued to 49inch pounds. (It’s the fixit sticks limiter I had). I took it out to shoot for the second time and...
www.snipershide.com www.snipershide.com

And yes, it was a ZCO above. OP slipped and said it was a 36mm tube and then edited his post, plus I found a very probable bit of ZCO reticle in an image he posted.

FYI: Looked at a post I made in that last thread with a series of broken links that strangely go to that the OP’s first post. Looks like I linked to posts by our departed friend Reubenski, whose posts are all deleted. Can’t edit my post as the thread is locked.

So I’m not retarded lol.

I have a bunch of the older M10 ARC rings and a couple Mbraces. The M10’s have been used on mainly Vortex stuff. Like G2 razors, PST II 3-15 & 5-25’s, and the lightweights: LHT 4.5-22 razors and LHT 3-15 razors. I’d imagine those last two have a bit lighter tube than the G2 lol.

Anyway, I think we’d all love some clarification from the manufacturers, but unless I’ve missed it, none is forthcoming. @karagias ?

I don’t know who to tag for ZCO.
 
#25
carbonbased said:
I don’t know who to tag for ZCO.
Click to expand...
@gebhardt02

But I thought this was all thrashed out in one of those threads you posted (the 2nd one, maybe....not inclined to re-read them right at the moment) and I "believe" ZCO said that 45 in/lbs would be ok.

Anyway, that's what I've been torquing ARC rings and ZCO 5-27 at.

I wonder about the M-Brace mount...personally, I don't really see the need for a one piece mount in my use...and I wonder just how far/close the ring clamps are to the turret bell housing and if that has any effect. I stay at least an 1" away from the furthest point of the housing (actually probably a bit more).

Also... @308pirate ...isn't this in your wheel house? Diff between effective clamping force of multiple screws versus one big honking one?

cheers
 
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#26
Thx for the info, @Baron23.

Also:

@gebhardt02 Comment in 2019 (paraphrased): “Use ARC torque specs. I wrote the manual.”
https://www.snipershide.com/shootin...-costs-4k-keeps-cracking.7108403/post-9994939

@gebhardt02 Comment in 2022, in that big cracked ZCO lens thread (paraphrased): “Do not use ARC torque spec. Use 35 in/lbs.”
www.snipershide.com

Top scope brand that costs 4k+ keeps cracking

Hey OP, what did Brand X (ZCO) say when you called them to report the same issue occurred again? Please don't leave us hanging and not come back with the verdict. I'm really curious to see if my theory is correct.
www.snipershide.com www.snipershide.com

Comment in 2022 by @Baron23 (I totally agree, btw):
www.snipershide.com

Rifle Scopes - Official Zero Compromise Optic News & Updates

One thing that might be worth clarifying is that there is a disconnect between the sticker that came on my scope and the owners manual that was included. My scope had a sticker saying not to exceed 20 in Lbs while the manual said don’t go over 25.
www.snipershide.com www.snipershide.com

@CSTactical, a ZCO reseller, response to Baron's post (directly above):
www.snipershide.com

Rifle Scopes - Official Zero Compromise Optic News & Updates

One thing that might be worth clarifying is that there is a disconnect between the sticker that came on my scope and the owners manual that was included. My scope had a sticker saying not to exceed 20 in Lbs while the manual said don’t go over 25.
www.snipershide.com www.snipershide.com

I'm quite sure I read a post from someone that seemed reliable that said there was a now-resolved tiny manufacturing defect on the outer edge of a lens, or the inner edge of where the lens fits into. This flaw was just enough to crack the lens when the scope was mounted.

There are also posts theorizing that some "misalignment of the lens seat to the lock ring threads" might have caused the issue. Here is one:
www.snipershide.com

Top scope brand that costs 4k+ keeps cracking

Unfortunately, this is the one off situation as it makes no sense. If you have followed Ted long enough and have observed his design principles, you may know what I mean. There is pretty good reason why ARC is not much more successful than it is. From the note you are making, I dont think you...
www.snipershide.com www.snipershide.com

Anyway, some may say this is water under the bridge, let sleeping dogs lie, etc. If it's a settled issue, please point me to the link. I see no rational reason to not come out and explain what the heck was going on. Unless there are industry or personal relationships at stake. Or, uh, legal reasons.

For example, @wooferocau (I like this guy, btw!) had some ZCO (and S&B) issues that he's never quite fully explained, and I wish he would. Explained as in what exactly was the issue…and I mean exactly. As in, "Manuf. said part A interfered with part B and…"

He did get his stuff satisfactorily resolved, however. He's gotten a bunch of flak for complaining, some deserved, some not, but I believe him.

Not harping on ya, @wooferocau, but just saying how I feel.

It's stuff like this that prevents a percentage of the small number of potential high-end scope buying people to avoid certain products, be it the scope or the mount.
 
Last edited:
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#27
carbonbased said:
Comment in 2022 by @Baron23 (I totally agree, btw):
Click to expand...
Damn, brother...I was pretty sharp back then when I wrote that...now, I'm an old, retired, idiot (gee, what a difference a couple of years makes! haha).

And thanks for finding 35 in/lbs. I couldn't remember. I do use 45 in/lbs with no issue and with 6.5 CM I think I'm fine with 45.

Now, I have had Leupold Mk 5 5-25 in ARC rings and went to 55 in/lbs without issue.

Only problem I ever had was very first time I mounted the ZCO and went straight to 55 and felt a little bit of binding (not bound...just a bit more resistance) on the parallax. I then stepped up to 55 (25, 45, 55) and had no issue.

And I absolutely agree....this should be clarified based on actual fucking engineering and...well, I don't think we've seen anything like that then or now.

Thanks and cheers
 
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#28
Thanks all for the replies and links. I had reached out to ARC with some questions but have not heard back yet. I think I will " hopefully " play it safe and use my Seekins rings. That is unless someone has other ring recommendations?
 
#30
carbonbased said:
For example, @wooferocau (I like this guy, btw!) had some ZCO (and S&B) issues that he's never quite fully explained, and I wish he would. Explained as in what exactly was the issue…and I mean exactly. As in, "Manuf. said part A interfered with part B and…"
Click to expand...
Oh! At least on the S&B front, I see @wooferocau mentioned yesterday that some grease specks shook loose onto the lenses when shooting his 50 BMG with his Schmidt 10-60.
www.snipershide.com

Arken EP5 7- 35 .. Standing in for some Alpha Glass

Over time i have had more than my fair share of expensive Alpha/Top Tier Glass fail ... Just recently i had 2 current Top Tier optics on 2 of my Desert Tech,s go down. While still waiting for this to be resolved i decided to go the complete other end of the scale...yep....."Cheap" China...
www.snipershide.com www.snipershide.com
The grease bit is mentioned further down in the thread by someone else that also had it happen to them.
 
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#31
carbonbased said:
Oh! At least on the S&B front, I see @wooferocau mentioned yesterday that some grease specks shook loose onto the lenses when shooting his 50 BMG with his Schmidt 10-60.
www.snipershide.com

Arken EP5 7- 35 .. Standing in for some Alpha Glass

Over time i have had more than my fair share of expensive Alpha/Top Tier Glass fail ... Just recently i had 2 current Top Tier optics on 2 of my Desert Tech,s go down. While still waiting for this to be resolved i decided to go the complete other end of the scale...yep....."Cheap" China...
www.snipershide.com www.snipershide.com
The grease bit is mentioned further down in the thread by someone else that also had it happen to them.
Click to expand...
It was a couple of S&B 6-36,s that suffered form internal grease splatter ...

The issues with my S&B 10-60,s is different........S&B Germany are on top of it , it is to do with going out of focus under recoil... all i can say i am afraid..

Agian ... the 50 brings a lot of optics undone !!
 
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#32
carbonbased said:
For example, @wooferocau (I like this guy, btw!) had some ZCO (and S&B) issues that he's never quite fully explained, and I wish he would. Explained as in what exactly was the issue…and I mean exactly. As in, "Manuf. said part A interfered with part B and…"



Not harping on ya, @wooferocau, but just saying how I feel.
Click to expand...
My ZCO issues ( 2 x 5-27,s and an 8-40) were to do with binding , parallax ...and in the extreme broken/failed parallax with POI shift after recoil..

It was all resolved as my dealer refunded me 100% for the scopes. I still have my original ZCO 5-27 which is still going strong..
 
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#33
wooferocau said:
It was a couple of S&B 6-36,s that suffered form internal grease splatter ...

The issues with my S&B 10-60,s is different........S&B Germany are on top of it , it is to do with going out of focus under recoil... all i can say i am afraid..

Agian ... the 50 brings a lot of optics undone !!
Click to expand...
wooferocau said:
My ZCO issues ( 2 x 5-27,s and an 8-40) were to do with binding , parallax ...and in the extreme broken/failed parallax with POI shift after recoil..

It was all resolved as my dealer refunded me 100% for the scopes. I still have my original ZCO 5-27 which is still going strong..
Click to expand...
Hey man! Thanks so much for chiming in. Really!

Nice to have that info in one thread.
 
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