BUIS Are Very Important

Mark Farage is no novice shooter. Mark checked the screws of his RMR to ensure they were properly torqued before he took a course with Ronin Combat Strategies. But during a 6 shot string drill, the screws flew off and so did his RMR. Without missing a beat, Mark managed to continue the drill with his BUIS and fired 6 shots in 1.78 secs.

Mark is shooting his Zev Technologies Glock 19. You can see the RMR mounted at the rear and a backup sight mounted in front of the RMR. It looks kinda like the picture below.


Here he begins the drill.



You can see the screws flying in the air.


The motion of the slide sends the RMR rearward.



Right into Mark’s cheek.




Mark told me he could not find the screws to see if they had stripped or if they had any blue loctite on them. The slide still has threads. It’s a new gun so when he checked the screws before the class he didn’t back them out to check for blue loctite. So now he plans to order replacement screws and keep some spares in his range bag. He will also add a little JB Weld or blue loctite to the screws.


Even though you plan for everything with the best intentions, the unexpected can happen. As Mark told me; “This was a legit and unpredictable equipment failure.” So stay in the fight and don’t let things disturb you from the task at hand as long as you can continue doing so safely.

Nicholas C

Co-Founder of KRISSTALK forums, an owner’s support group and all things KRISS Vector related. Nick found his passion through competitive shooting while living in NY. He participates in USPSA and 3Gun. He loves all things that shoots and flashlights. Really really bright flashlights.

Any questions please email him at nicholas.c@staff.thefirearmblog.com


  • Marc

    Screws don’t hold when tightened against aluminium, no matter how you torque them. Always use loctite.

    • Nicholas C

      But don’t the screws screw into the steel slide? I don’t think the slide is aluminum.

      • Marc

        Most friction that holds screws is underneath the head of the screw, not the threads. I learned that after constantly losing my Al grip panels despite torquing them harder every time they came loose, to the point of actually damaging them. Only loctite finally kept them from falling off after a few mags.

        • dan

          Are you sure about that? You want to reconsider where the friction of a screw is located? Because that logic wouldn’t work for set screws that don’t have a head.

      • Both are steel.

  • Dooos

    RMR just wanted to kiss him so much it tore itself free from its screws.

    • FourString

      Thirsty RMR haha

  • gunslinger

    blue loctite.. 242? We are using that for a customer. They are very detail oriented about that, and torque settings. procedure to ensure proper torque and such. basically we found out we needed to apply the 242, torque to the correct setting within 10 minutes (the dry time for 242) if the QC on the torque failed, we’d need to clean and start over again. 242 has a 24 hour “setup” time.

    i don’t get why you would use loctite, then back out the screw to double check it has it. if you did, aren’t you just breaking the bond of the loctite?

    • I find that sometimes a single application doesn’t do the job, if the fit between screw and hole is loose. Sometimes a 2nd application on top of the build-up of the first does a better job of locking the screws.

  • Zachary marrs

    Once your glock looks like that, don’t be surprised if it tries to self-destruct

    • iksnilol

      Don’t be surprised if it self destructs even if it is unmodified.

      • Sam Schifo

        Why the hate for Glocks?

        • iksnilol

          Not hate, disdain.

          I find them to be badly made/designed and way overpriced (except when buying a used one from the police). The fanboys don’t help either (James Yeager is a good example).

          Please note that I am not a gun snob. I use pretty much what I can get.

          • Sam Colt

            What specifically is badly made on a Glock compared to a similar gun like a Ruger or S&W?

          • iksnilol

            Have no experience with Ruger or S&W. What I find bad is a plastic trigger mechanism and sights. The grip is pretty bad, both angle and comfort. Let’s not forget that it is a pretty unsafe design, no safety or decocker. Also pretty overpriced for what you get, can buy a CZ for the same amount of money.

            I can work with them but I consider them dump guns.

          • Tothe

            It’s perfectly safe AFAIK if you keep your booger hook off the bang switch.

          • iksnilol

            That is naive. How many people (mostly 5-0) shot themselves because something snagged on the trigger? At least the XD has a grip safety which requires you to hold the pistol properly before you can shoot. The safety is also easy to disengage when you want to reholster.

            You can say you are properly trained to avoid that and all but s*** happens… and I like to avoid it if possible.

          • Tothe

            The stories I have heard have involved specific typs of minimalist CC holsters, and not the kind I would use. DA revolvers also have no external safety either, and lack the trigger bar of Glocks so any portion of the trigger being pulled can cause an AD. It isn’t a flaw, it’s a characteristic to be acocunted for.

          • Torrorojo

            Compare the trigger on any smith or ruger revolver with that of a stock Glock. It takes a very conscious effort to make the 6 gun go bang

          • Tothe

            Is more force needed? Yes. But anything in the trigger guard will make it go bang if the operator is negligent. It’s only a fairly small difference in scale of force, not in kind of AD. And a S&W Model 10 doesn’t have that nifty trigger bar that also needs to be pressed, and does have a very smooth trigger pull.

          • lucas p

            if you have no experience with the most comparable firearms in the price range, it doesn’t really seem as if your qualified to say whats crappy and whats not..

          • Tothe

            I have shot Glocks. I know some people love ’em and some people hate ’em. I don’t own one myself, but a Glock 19 does tempt me. So does a Springfield XD, or Ruger’s compact options. Doesn’t it suck when we have so many choices for things, so we can fit our individual budgets and preferences?

          • Crosslay2

            I’ve owned and ccw’d a Glock 22 since 1991 and it’s never failed me. What is this “bad design”? Can you elaborate? It would be enlightening to hear about for me and the other millions that choose Glock…including just about every LEO/Military group you can think of. And I own a Wilson Combat Professional and a Sig Sauer P226 MK25, so, it’s not as if I’m the “fanboy” you speak of.

          • iksnilol

            If it works for you go ahead, for me it doesn’t work that well. I have options that are better (for me) for less money.

            Bottom line is, I find the Glock badly made/designed but it doesn’t mean that other people find it so. As long as you are comfortable with it and can hit your target then you are golden.

            Edit: I didn’t mention that I don’t use revolvers except in limited circumstances. So the whole “revolvers don’t have a safety either” becomes a moot point for me.

  • tirod

    Blue loctite is hand pressure sensitive, ie you can disassemble it without using heat. Run that gun warm enough it will loosen it up. Same for red – makes no sense to use that on AR’s when you can definitely exceed the heat limit for disassembly in about two mags fired rapidly.

    The real issue is fastening things to a dynamic operating part with tiny screws. It’s manual action receiver tech and not necessarily applicable to sticking something on a moving slide that is being whipsawed back and forth by a delayed reaction to a gunpowder charge. Got to ask, do you ever see little screws holding things onto the pistons of a motor?

    It’s why rear sights are generally held on by dovetailing, not tiny screws and glue.

    As for the use of BUIS, it’s a competition gun, he completed that stage instead of a DNF – but it goes to not getting reliable equipment and KNOWING your are making a poor decision that prompts having a back up sighting system. Had the primary actually been proofed as being reliable in the first place, there would have been no nagging doubt that led to adding even more sights in the first place.

    Competitors make those decisions based on not wanting to be substantially penalized for an equipment mishap, same as NASCAR has dual ignition systems to cover a failure on the track. But it also goes to why use something known and that has a history of failure to begin with.

    Tiny screws using glue to hold them is isn’t hard use tech – had the sight been mounted correctly then the worst case situation would have been electrical failure or a glass screen broken, which is the dominant issue with battle optics. Judge for yourself is you “need” BUIS on a gun – or if you really need to upgrade your equipment and rely on better quality. Most civilians don’t bother with BUIS, they were dropped from hunting rifles 40 years ago.

    If you are in a top tier use demographic, backups and redundancy can be important, but this little mishap isn’t justification for including the dead weight of BUIS on every gun you own.

    • Nicholas C

      So how does one properly install a RMR? Or similar MRDS? They are all fastened to something using tiny screws.

      • iHAL

        Krazy Glue, duh.

        • Zachary marrs


      • J.T.

        Just because a MRDS and slide can be modified to attach to each other, doesn’t mean they should. IMO putting any optic on a slide is just asking for trouble.

      • The Trijicon comes with screws already treated with blue Loctite. You can always add a bit more.

      • Put it on a frame mount, so that it’s not flying back and forth every time you pull the trigger.

    • dan

      So what you are saying is buy something that will never fail? Ever? Where can one purchase such equipment? I have money to throw at the manufacturer who produces such superior products. I agree I don’t need back up sights on everygun I own, but the ones that are used to protect me or those I would perhaps use in competition you can bet I will have back up sights because eventually no matter how high of quality your equipment is, it will fail. Redundancy is a good thing when your life depends on it.

    • n0truscotsman

      From a practical standpoint, i agree with you.

      blue or red loctite has worked on pistol optics i have seen, and i loctite blue the shit out of any screws on my boom devises.

      If you are really concerned, rockset it 😛 (and the optic will stay on the handgun longer than the lifespan of human civilization).

    • high drag

      “As for the use of BUIS, it’s a competition gun, he completed that stage instead of a DNF – but it goes to not getting reliable equipment and KNOWING your are making a poor decision that prompts having a back up sighting system. Had the primary actually been proofed as being reliable in the first place, there would have been no nagging doubt that led to adding even more sights in the first place.” -tirod

      That is a ridiculous and barely thought through statement. Every combat rifle that has an optic in the military or L.E. community has BUISs. I never saw a single ACOG fail in any manner (nor have I actually heard someone say “Mine did”) the entire time I was in the Marine Corps and guess what every single rifle had on it? BUISs. The majority of L.E. patrol rifles “10-8” in America have red dots and guess what else they all have? BUISs.

      To say that adding BUISs to a weapon (rifle/pistol/shotgun/death ray/whatever) is done because the shooter “knows they are making a poor decision” and have “selected an unreliable, unproven primary” sight is ignorant and out of date. If you put an optic on a combat weapon (any weapon) you put BUISs on it because shit happens. “Top tier user” doesn’t have crap to do with anything. That’s like saying only “top tier” drivers should wear seat belts or only “top tier” unicorn jockeys need to install a horn protector.

      “This little mishap isn’t justification for including the dead weight of BUIS on every gun you own.” – tirod

      BUISs are dead weight? A set of suppressor BUISs (because you need suppressor height to use with an RMR) weigh less than a single round of 9mm, but I guess that’s to much dead weight. I bet your going to be the same guy who recommends that officers down load their magazines to 5 rounds to “save the dead weight” besides, they should be able to hit their targets the first time because they are trained officers and statistically will not ever encounter more than 5 targets in a single gunfight, right? Your statement should have its own meme it is so ridiculous.

      The shooter should be commended that they thought through a situation and then proved the concept without having some internet moron spout off about how optics should only be used if they’re “proven” (whatever that means to tirod) and how if they are “proven” they will never fail in any situation and so including 0.3oz of BUISs is “dead weight”.

  • claymore

    Common problem. I had the scope ring mount on my remington 700 in .308 work loose after 4-5 shots when using with a suppressor. I guess the back and forth movement caused by the suppressor exerted “different” vibrations on the small screws even when using red loctite they just wouldn’t stay secure.

    I finally solved the problem by pinning the mount to the receiver with one small drift pin mounted vertical. No problems after that the screws stayed in position when normally tightened.

    I surmise the pin prevented the mount from moving back and forth under stress.

    • Phillip Cooper

      The drift pin is exactly the solution. Easiest way to implement this is to drill and tap a hole for a small grub screw. 4-40 comes to mind as the size I typically use as a stop.

  • vereceleritas

    And that’s why eye protection while shooting is very important as well.

  • Phillip Cooper

    Adding JB Weld to the screws would be HIGHLY ill advised. Might as well just epoxy the thing on if that’s how you’re going (JB Weld IS epoxy).Blue Loctite is the preferred solution with a fastener of this size (honestly, Green would work), and Red Loctite if you want to go nuts (removal will require heat- far more than this weapon will produce in normal operation)

    • Very true don’t use JB on a gun. Blue Loctite is the way to go and is recommended as such my manufacturers.

    • Scott Thompson

      Green and red are both the same temp rating. Green is designed to “chase” threads on parts already installed.

      • Phillip Cooper

        Have you actually ever spun a wrench as a mechanic?

        Loctite Green:
        Yes, is a wicking grade locker (I’d forgotten that one, thanks- I don’t ever use the functionality). The important thing to note is that it only requires hand tools to disassemble. Some key words and phrases: “designed for easy removal” “for small fasteners”
        (I would not use it on a firearm, don’t think it’s up to the task as this is a rather extreme environment even though the material is rated up to 450deg)

        Loctite Red:
        Some key phrases: “PERMANENT” “disassembly requires localized heat (550deg F), hand tools, AND disassembly while hot” “temp range up to 550degF” :”for 1/4-3/4″ fasteners”

        Quite honestly, I feel Loctite Red is counterindicated, and Loctite Green is not up to the job. I’d use Loctite Blue as it won’t require heat to disassemble, is a medium-strength solution, and is actually intended for larger fasateners (there’s no reason you can’t use it on smaller fasteners, so long as they’re high-quality- there’s concerns of rounding out the head trying to get enough torque into them to pop the loctite loose).

        I use this stuff just about every day- used to be professional requirement (mechanic and shipboard work), now it’s for fun (I build Jeeps and modify cars). I know of what I speak. I have all of these products in my toolbox, and believe me when I say Loctite Red is PERMANENT unless you heat the hell out of it and go at it while hot. Green is good for low-stress, non critical applications- you’ll hardly tell it’s there when disassembling.

  • SafeArmsReview

    Good on him for keeping the forward momentum = accomplish the mission regardless.

  • 3331

    I think the real lesson here is not to rely too heavily on new or untested equipment.
    And it also demonstrates that there are smarter ways to mount a red-dot on your gun.

  • fjfar80

    Just a little additional information: (1) I just purchased the gun and this was the first time that I was putting it through its paces. (2) I did not back the screws out and test for Loctite as that would have defeated the Loctite and forced me to apply additional. (3) This was a fun day of shooting with Ronin instructors, friends, and guests from OTG Hex – so, it was the perfect opportunity to test this gun out for weaknesses – I found one by the way. (4) I have purchased new screws and mounted it with Blue Loctite – in addition, I have found putting a very, very, very small amount of JB Weld on the bottom-side of the screw head will create just enough adhesion between the mounting surface and the screw head to keep things where they are. If you put a very, very, very small amount – the epoxy bond can be broken with the proper application of torque. The trick is putting just enough to create a little adhesion without putting too much that will force the heads (hex key in this case) to be stripped when trying to reverse them out. (5) I think it is important to test any gun in a low stress environment either before you are going to run it in competition or depend upon it for your safety or the safety of others. I was purposely running this gun hard and I was actually looking for points of failure – something I do with all of my competition or carry guns. (6) In regards to Glocks, they are great guns and ZEV does very good work on them – if you don’t like them that’s a personal opinion vs. a data driven conclusion. Running a RMR on a Glock has been proven in combat – however, there are weaknesses to attaching a RMR to any handgun. You just need to be aware of those weaknesses and be prepared to adapt and conquer. In addition, adding a RMR provides a great “ledge” for single-handed manipulation of the gun.

    • Phillip Cooper

      Thanks for .posting

      Regards using a tiny (TINY!!) amount of JB Weld on the screw head- I might suggest using a lockwasher instead. Possibly, a little white glue. All you’re trying to do is prevent initial movement. I would not use superglue, as it’s, well.. super.

      Lockwasher is the preferred solution. I’m surprised they don’t provide it from the factory.


    Why you need to put your gun together yourself so you know it’s done correctly… and if you can’t trust yourself, just don’t mess with your gun.

  • David Corner

    You should look for round broaches