UM Tikka rings are not recommended for cartridges larger than 7mm PRC?

[Schmo]

This is a valid point, but at the same time they aren’t building complex devices. Not figuring out sufficient torque specs for a scope mount is basic stuff. Engineering 101. Some very simple and inexpensive testing should’ve and would’ve revealed this issue early on. Not getting something so simple figured out at the testing stage is inexcusable.

You’re really overblowing an issue here. I didn’t know about this until this thread. Mounted them per UM’s instructions, and they’ve held zero perfectly. Notice that no one came here talking about zero shift, just that their pins were bent. UM is aware of the issue, and they’re trying to correct it. They’re also probably the most transparent company in this industry.

 

[HuntHarder]

You’re really overblowing an issue here. I didn’t know about this until this thread. Mounted them per UM’s instructions, and they’ve held zero perfectly. Notice that no one came here talking about zero shift, just that their pins were bent. UM is aware of the issue, and they’re trying to correct it. They’re also probably the most transparent company in this industry.

If you get bent pins, wouldn't it be really hard to have not had a zero shift? Essentially the ring moved to create the bend.
I have these on 4 different Tikkas with nothing but good to say about them. The different torque values from video to package was weird, but being on RS, I was able to figure out a #. Mine are all on smaller cartridges, so im not gonna sweat it too much. If I had them on larger cartridges, I would expect UM to make it right, which I am sure they would.

 

[Liv2HntBigBullz]

You do know that Ryan has nothing to do with running unknown munitions right? He owns this site and a podcast.

This really isn't about Ryan, but he sure doesn't have a problem promoting UM either...

Check the socials, lots of time in the shop "repping the brand"

 

[Ryan Avery]

The Rok community has been a huge part of UM success but the more we see stuff like this, the less faith I have in where I choose to spend my cash. Rokstock, UM rings, etc...seems like a company over their skis and I also find it interesting how quickly Avery passed the buck early in this thread. Whoops, now I'm too busy and too many irons in the fire wasn't my idea...

It's hard to pass the buck when you never had an issue. I have used these rings for the last few years on every hunt my wife and I have been on. I have shot more rounds through these rings than anyone outside of Form. NOT ONE ISSUE! Nor had I heard of a problem, and I have drop-tested them numerous times. So, stop the bullshit. If I were passing the buck, I would have nuked the Rokstok thread and this one early on. I don't work for UM, nor do I have knowledge of their day-to-day operations. I heard about this first on this thread. I personally don't think there is an issue if the rings are probably installed. UM could have done what every other company does and said nothing, and made an inline change. UM will make mistakes just like every other company that moves this industry forward, and you guys will be here to whine about that, too.

 

[Ryan Avery]

This really isn't about Ryan, but he sure doesn't have a problem promoting UM either...

Check the socials, lots of time in the shop "repping the brand"

Always use a local gunsmith, and they sell Rokstoks.

 

[Ryan Avery]

This is how I set up all of Tikka's and never had an issue.
300 WSM 800+rounds
Three 6UM 2000+ rounds
6CM 2000+ rounds
.223 10,000 rounds

Action screws 55-inch pounds
UM Tikka Rings 50 Inch pounds on clamp screws, use two pins; the holes depend on the scope, 25-inch pounds on the ring screws.
Paint pen on all screws


SO you might see my confusion on this issue.

 

[rbutcher1234]

It's hard to pass the buck when you never had an issue. I have used these rings for the last few years on every hunt my wife and I have been on. I have shot more rounds through these rings than anyone outside of Form. NOT ONE ISSUE! Nor had I heard of a problem, and I have drop-tested them numerous times. So, stop the bullshit. If I were passing the buck, I would have nuked the Rokstok thread and this one early on. I don't work for UM, nor do I have knowledge of their day-to-day operations. I heard about this first on this thread. I personally don't think there is an issue if the rings are probably installed. UM could have done what every other company does and said nothing, and made an inline change. UM will make mistakes just like every other company that moves this industry forward, and you guys will be here to whine about that, too.

Thank you Ryan. This is basically what I have been saying.

 

[BigCountry49]

Does anyone know what is causing the rings to move under heavier recoil? Is the clamp not machined correctly, bolts not specified for torque required, etc. They seem well made but I bought them under the impression they would be more secure than other offerings of similar weight. I’m not buying the idea that over torquing the bolts is the obvious solution. I have to assume that bolt’s torque spec was based on the grade, diameter, thread pitch from whoever made the bolts.

 

[wyosam]

Good to hear.

I have to agree with @SDHNTR that using a cartridge leaves a lot of ambiguity In the benchmark. Specifying a recoil impulse as well would be helpful as that accounts for rifle weight, charge weight, and bullet weight much better than a head stamp.

Have you thought about redesigning the pins to be more like a socket head screw? Have them sit lower, the head would support the shaft and avoid bending, and the friction between the head and top of the rail should protect the screw from some of the sheer forces. A #6 48 round socket cap screw would probably work.

Of course, the slots in the ring bases would need modification.

Exactly what I was thinking after looking at a picture of the UM pins. What you describe is exactly how I pin the rear ring on Sportsmatch rings. I just use some I had in my parts bin, and turn the head down (diameter and height) a bit so the ring just slips over, then push them hard forward while torquing. Being short means less leverage on the screw, and having the friction of screw head torqued against action makes it much stronger. I have set quite a few up that way and they don’t move. I’ve done the front ring as well if a threaded hole gives better placement.

I’ve not had hands on the UM rings but if the edge of the hole that pin goes in isn’t parallel (or has an imperfection or something) to that pin and is hitting at the top of the pin first, I could see bending the pin easy enough.


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[BBob]

I’m not buying the idea that over torquing the bolts is the obvious solution.

Are they over torqued or did they just change the torque specification? I don’t have any here to look at the fastener size but if it’s a grade 8 10-32 then 55 in lb would be easily appropriate and 60 not out of range.

 

[BBob]

I’ve not had hands on the UM rings but if the edge of the hole that pin goes in isn’t parallel (or has an imperfection or something) to that pin and is hitting at the top of the pin first, I could see bending the pin easy enough.

It’s a machined recess and highly unlikely it isn’t square to the bottom of the ring. The rings are 6061 so I suppose with enough recoil and not enough clamping force the aluminum might start to yield (dent).

 

[bowrunner81]

I read through the posts but didn’t see anywhere where folks who have noticed bent pins or slippage had a zero loss or group size increase? I’m very curious is anyone has, and if I missed a post where someone had, chill. I am a structural engineer and have done plenty of steel design. The bent pin obviously means that the rings slipped a measurable amount, but the load required to create an actual shear failure in the pins is far and above what even magnums can produce if you take into account the friction of the ring clamp as well and maybe the pin along. I didn’t run the numbers and I don’t have time to. So if you are noticing bent pins, at least you know you are fully engaging a pin and that ring won’t slide anymore, especially if you are yielding that pin. I can’t say I love the idea of a bent pin, but in a crappy rail design like the one on a tikka, it provides assurance that you are not slipping anymore.

Although the changes in torque specs is a mess and discrepancies between videos and their website or wherever that discrepancy is shouldn’t happen, I do believe that everyone makes mistakes. I don’t think this was a mistake on posting the wrong torque values, but more so the folks involved didn’t agree on the correct torque setting to publish. I have a set and had it on a 6.5cm previously and moved the scope and mounts to a 6cm build with a different action. I had a hard time getting one of the pins to screw into the new action but I got it in there. I didn’t look at it close enough to know if it bent but it must have. I used whatever torque settings were specified on their website a year and a half ago (which I cannot remember) on the 6.5 cm and the current torque settings on their website two weeks ago for the 6cm, which I’m reading is 55 in-lb for the bases and 30 in-lb for the scope. I’m not too worried.

 

[Sundodger]

Does anyone know what is causing the rings to move under heavier recoil? Is the clamp not machined correctly, bolts not specified for torque required, etc. They seem well made but I bought them under the impression they would be more secure than other offerings of similar weight. I’m not buying the idea that over torquing the bolts is the obvious solution. I have to assume that bolt’s torque spec was based on the grade, diameter, thread pitch from whoever made the bolts.

I wish it was that simple... But hopefully UM has a nice fishbone diagram going.

The correlation between what you calculate/simulate and the real world is the worse for bolted joints than anything else I have done in engineering.

I don't know UM's design philosophy, but I can tell you what happens at OEM's. All those calculations/simulations/rules of thumb happen to just get you in the ballpark. Then you test statistically significant number (a ton) of samples with load cells; using production intent fasteners/coatings, Production intent thread form/process, production intent threaded material. Now you iterate the design and testing, but hopefully not too many times.

This is because tiny differences are a big deal here. When you start getting to the fastener to the proof load that's required to keep a properly designed joint together, almost all your applied torque is going to friction. Tiny differences in thread form (class, tapped/rolled, etc.), alloy of the thread material, alloy of the under head material, surface finish of the under head and threads, cleanliness, coatings, paint, etc.

Here is a great case in point, many years ago most grade 8 bolts were Cad plated. There was an industry switch to zinc plating's, that was an absolute disaster for some joints, requiring redesign/new processes, and totally inconsequential to others.

 

[Kauaihunter]

Moving forward the torque spec has been increased/updated. If someone installs pins in each base and torques to 55in/lbs and still has slippage/bent pins occurring, then there could be cause for concern.

Has this happened yet?

I received another set yesterday and will be switching out rings/scopes between rifles, again, with no concerns. Onward…

 

[Harvey_NW]

Moving forward the torque spec has been increased/updated. If someone installs pins in each base and torques to 55in/lbs and still has slippage/bent pins occurring, then there could be cause for concern.

Has this happened yet?

I received another set yesterday and will be switching out rings/scopes between rifles, again, with no concerns. Onward…

On my 6.5 PRC I installed a pin in the front ring and torqued to 55in/lb with thread locker, I haven't touched it since I validated my hand load and established zero in August of '24. I think it's a non issue, but I'll probably put pins in both bases of my 7 PRC when I assemble it this winter.

 

[Kauaihunter]

On my 6.5 PRC I installed a pin in the front ring and torqued to 55in/lb with thread locker, I haven't touched it since I validated my hand load and established zero in August of '24. I think it's a non issue, but I'll probably put pins in both bases of my 7 PRC when I assemble it this winter.

I have both pins in my 7mag that I bought in September 2024 and have no issues with over 200 rounds. 3150fps

 

[BBob]

The few sets I’ve installed I used a pin for each ring. I don’t know why you wouldn’t unless you had an odd ring spacing that wouldn’t allow for it.

 

[Kauaihunter]

The few sets I’ve installed I used a pin for each ring. I don’t know why you wouldn’t unless you had an odd ring spacing that wouldn’t allow for it.

 

[Sacrvrrat72]

I wish it was that simple... But hopefully UM has a nice fishbone diagram going.

The correlation between what you calculate/simulate and the real world is the worse for bolted joints than anything else I have done in engineering.

I don't know UM's design philosophy, but I can tell you what happens at OEM's. All those calculations/simulations/rules of thumb happen to just get you in the ballpark. Then you test statistically significant number (a ton) of samples with load cells; using production intent fasteners/coatings, Production intent thread form/process, production intent threaded material. Now you iterate the design and testing, but hopefully not too many times.

This is because tiny differences are a big deal here. When you start getting to the fastener to the proof load that's required to keep a properly designed joint together, almost all your applied torque is going to friction. Tiny differences in thread form (class, tapped/rolled, etc.), alloy of the thread material, alloy of the under head material, surface finish of the under head and threads, cleanliness, coatings, paint, etc.

Here is a great case in point, many years ago most grade 8 bolts were Cad plated. There was an industry switch to zinc plating's, that was an absolute disaster for some joints, requiring redesign/new processes, and totally inconsequential to others.

If you think other scope ring OEM’s are doing that you are naive at best. Won’t disagree in a perfect world this would be the way, but it is not happening in real life.

 

[Marbles]

Moving forward the torque spec has been increased/updated. If someone installs pins in each base and torques to 55in/lbs and still has slippage/bent pins occurring, then there could be cause for concern.

Has this happened yet?

I received another set yesterday and will be switching out rings/scopes between rifles, again, with no concerns. Onward…

I would say if someone has a zero shift. I just see the threaded pins as a limited use item. Primary because if the bend is not indexed the same work the steel back and forth will weaken it.

I had no zero shift. If not moving the rings from rifle to rifle, it really doesn't matter if the pin bends because once bound up it still would require a large sheer force to snap the pin. Being soft steel, it is less likely to fail from a fracture and rather should yield, but the aluminum ring material would likely yield first. While I can see a shiny line where the pin engaged the ring, there is no deformation to my eye.

To be clear, I don't know what lead to UMs change in recommendation, but the bent pin I experienced is not something I consider significant. I brought it up in speculation as I rather doubt they have had a cracked ring.

From what @Salmon River Solutions said, I suspect slipping was the issue, but we don't know if anyone using a recoil pin has had slipping significant enough to change zero.

I think not using a recoil pin on a Tikka dovetail is foolish regardless of the ring.

I was looking last night, and it does appear the clamp is designed such that tightening the screws engages the ring and the top of the rail, which is how it should be rather than only placing the load on the dovetail edges. But, it is hard for me to say with certainty.