Mauser M12 problems and Hexalock problems

[Bule Jagter]

I'm not sure how I ended up having issues with both, my new Mauser M12, and the new Hexalock scope ring mounts, but it's enough to have convinced me to contact Blaser, asking for help. I thought I'd also post it here, to see if anyone can explain what happened.

My M12 is new (It was a demo at Guns.com) I'm the first owner. All I could do for the past three or four weeks, was enjoy the smooth action of the bolt, because, as you can guess, the Hexalock mounts were out of stock everywhere. I back-ordered Hexalocks from Eurooptics, and received them Saturday. I read through the instructions carefully, and found one video on youtube, which helped a lot. The torque, according to the instructions, seemed a bit high, but I followed the instructions and used my one year old Wheeler fat wrench, set at the correct torque on the torx screws for the Hexalock bases.

After that, I slowly learned how the rings attach. As I was getting the rings lined up, my hand pushed the bolt up a little, and I could feel it was very tight. I then removed the bolt, but it was not smooth at all. When the bolt was completely removed, it fell into two separate pieces. Now I can't get the bolt back together. With the firing pin and safety out of the bolt, I thought I should try putting it back in the rifle to see if it is smooth. It did not improve anything.

I can't imagine the torx screws for the Hexalock were too long and sticking into the barrel far enough to impede the travel of the bolt. I see no scratch marks on the bolt, either.

At this point, I decided to try removing the Hexalock mounts in order to attempt to slide the bolt into the receiver, and see if it actually was the torx screws going too far into the barrel. Those torx screws are very small (t-10). As I tried to remove the torx screws, it stripped the heads. Now I have a bolt in two pieces, stripped heads on the torx screws holding the bases on the receiver, and confusion as to why the bolt will not operate smoothly. In fact, it is very difficult to move the bolt at all, within the action.

I was very happy to finally own a Mauser. I hope these problems can all be alleviated without costing any money. Does anyone have any suggestions, or an explanation of what happened?

 

[Fastrig]

Wow, I’ve had Zero problems with my M12 Max 9.3x62 with the Hexalock mounts. The mounts go on easy, return to zero every time, and actions feeds like butter. Sorry to hear you are having issues. Sure Mauser will get it corrected for you.

As an aside, I had a gun smith mount those rings as they are a bit different and wanted to make sure they were done right.

 

[Bule Jagter]

Blaser USA, in Texas, responded quickly to my email. I was told to ship my Rifle to them. I shipped it last Saturday, and now I'm waiting to learn what they say and do, after receiving it.

The installation of the bases and rings is definitely different, but I followed the directions precisely. The torx screws are very small considering the recommended torque to be applied per the directions (5NM for the bases). I believe less torque is actually needed.

Hopefully, everything will be taken care of by Blaser, quickly. I'll post again, after they fix it.

 

[Bule Jagter]

I just received my M12 back from Blaser last Friday. It took a long time, but they replaced the torx screws on the hexalock bases, installed the bases for me, and apparently put the bolt back together. The repair letter didn't even mention repairing the bolt, so I guess I just didn't know how to put it back together. I've mounted the rings and my Leupold VX5-HD. Everything looks great, and the bolt moves smoothly. It was covered by warranty, and I'm happy. The only downside is the fact that it's deer season now. I still haven't shot it, and I won't until after deer season is over, in early January.

 

[Clavdivs]

I too have had problems with Hexa Lock.

Instructions were not available on the web

The printed instructions are incomplete and nonsensical.

Although it is recommended to glue bases and screws in place with a "suitable adhesive" none is specified or recommended. I used Loctite 243 for screws and 609 for bases.

The specified torque (5 Nm) likely exceeds the maximum torque for a Torx 10 and resulted in stripping the head's teeth. Here are max torque setting as given by Wiha (4.5 Nm)

Typical Dimensional and Torque Specifications of Torx Tools

Wiha Torx Tools SEE ALL TORX TOOLS SEE ALL SECURITY TORX TOOLS For use with Internal Socket Head Type TORX Screws Size InchP to P MetricP to P Maximum Torque Range Wiha Bit Wiha Screwdriver T1 .031 .81mm .02 to .03 Nm ORDER T1 TORX BIT ORDER T1 TORX SCREWDRIVER T2 .036 .93mm .07 to .09 Nm ORDER...

www.wihatools.com

The words "The HexaLock mounting feet are aligned in the direction of the loading opening so there is just a small gap", do not constitute an intelligible instruction.

There is a mention of "squares" as indicated in figures 1 and 7 but no information on what these tools are or what they are used to achieve.

Having installed the bases, the rings are adjusted using a screw which seems to be already secured with locking compound. Most people report the adjustment is "fiddly". This is because the adjusting screw has a coarse thread and moving it by 1/10 turn causes the levers to be too tight or too loose. In any case, when the locking lever is closed the rings are not really secured much for rotation but only vertical and lateral movement.

The words "we recommend that you fasten the rings to the telescopic sight and also use a suitable adhesive to glue the screws" may indicate that the ring be glued to the scope, not something most people would like to do unless an easy to remove adhesive is used.

When attempting to close the levers, these tend not engage easily at the start, possibly due to insufficient chamfering.

Finally when scope alignment tool is used on the two rings I found one was higher by a small amount (about 0.4mm), enough to necessitate lapping on the rings to achieve proper alignment.

I have not yet been able to install my scope and have doubts of the quality and design of the HexaLoc system.

Certainly, I prefer a Sako machined receiver with integral tapered bases and Optilock rings and do not understand how Mauser can produce a scope mounting system that requires hand lapping for a good fit, or instructions that rival the Chinese for obscurity. I will continue to try to salvage the installation but need to order new screws, a loctite solvent and maybe extractors to remove the failed screws.

 

[mark-hunter]

@Bule Jagter
So far, it turned, OK.

I will add one comment, and just in case this was adressed in previous posts, I must have skipped it, so in that case, I appologise.

If you were using a thread locker, then while it is still liquid, it may act as lubricant, and the screws can be turned too tight, despite proper torque applied by wrench.
This actually happened to one of my firends, all done by the book (manual), and ended up, with damaged optics.

Lets hope, the problem is solved by blaser. Let us know how it all works, after the test.

 

[Clavdivs]

Bule Jagter: Sure Loctite may affect the maximum torque specification.

eg: from

https://www.fastenal.com/content/merch_rules/images/fcom/content-library/Torque-Tension%20Reference%20Guide.pdf

"Torque=KDF, where K is the estimated torque coefficient (for full details contact engineer@fastenal.com). K = 0.12 when using EcoGuard™ coated nut, bolt and washer K = 0.15 for “lubricated” conditions including EcoGuard™, some oil, tapping fluid, etc. K = 0.17 for some anti-seize, thread lockers, and some plain conditions K = 0.20 for zinc and dry conditions K = 0.12 is listed for A193 B7, which would be used for some general PTFE coatings When using zinc plated lubricated with wax prevailing torque lock nuts, the K value can vary between 0.12–0.18. Use Prevailing Torque All-Metal Nut chart if using this style of nut. D = Nominal Diameter F = Clamp Load"

My point is that Mauser should provide installation instructions with a recommended torque setting that will be effective without stripping the heads of bolts and specify the required adhesive.

Better yet, why not improve the design of the Mauser rifle and bases to include a machined recoil lug, tapered recess or other mechanical structure so as to avoid having the stick the mounts on with spit and gum?

 

[sestoppelman]

Have heard these HexaLocs can be a PITA as well as expensive. I decided against trying them.

 

[Fastrig]

Have heard these HexaLocs can be a PITA as well as expensive. I decided against trying them.

I don’t agree with the PITA adjective, but they have to be mounted properly and the instructions provided are pretty awful. When mounted properly they work very well, hold your zero, etc.

 

[sestoppelman]

I have read several accounts on the difficulty of getting them right.

 

[Clavdivs]

BTW Although the Hexalock bases are steel the rings are aluminium. On my M12 I had to lap the rings with a 30mm bar until the scope alignment pointers would match.
I would not have purchased them if I knew they were aluminium or if the needed lapping like cheap rings.
I can feel the steel screws digging into the aluminium as they are always under stress because the top ring must be compressed for the screws to fit. I suppose that's why Mauser wants the scope glued to the rings, something I have never see done, as there is not much holding those rings together.

 

[JohnCZ]

Love my 30-06 M12 Expert, went with Warne steel bases and steel rings with an 2MOA Aimpoint 9000L.

 

[MS 9x56]

So much for the excellent German engineering. If it takes an engineer and adhesive to “properly” install them I would go with Warne rings also.

 

[JohnCZ]

Love my 30-06 M12 Expert, went with Warne steel bases and steel rings with an 2MOA Aimpoint 9000L.

Thought I'd add a photo, I had to trim the front extension base and re-blue as I did not want it hang over the front or rear of the receiver. Rifle weighs a light 8.1lbs with optics.
Cheers
John

 

[MD Driver]

Yes sir, a veteran of wrestling with Hexalocks here as well. Learned the hard way that normal, perpendicular application with a torque wrench would strip the screw heads. Ended up getting new screws and then applying considerable downward force while turning with a Torx driver, and then carefully checking the torque with the wrench. I'm sure they're overtightened.

My M12 is one of the older early guns, that supposedly had a mounting screw patterns and receiver dimensions similar to the M98, whereas the later guns were patterned after the Rem 700 dimensions(?) Having several Rigby Highland Stalkers and a Mauser M98, I thought Hexalocks on all of them would result in a lot of scope flexibility for the four rifles. Wrong. The M12 wasn't even close. No big deal, as the others rate several Swaros, and I just dedicated a Zeiss V6 for the M12, and removable for its iron sights.

With all four however, none was an instant, easy mounting and adjusting experience. Now that they're on and adjusted, I'm pretty satisfied but overall I wouldn't recommend this system at all. I think there are much better options available.