Hints and tips for mounting red dot sights on firearms

 

The state of the art in so-called red dot sights (which, confusingly, also come in green, and may be a simple dot, or a circle-dot, or a more complex reticle) has advanced considerably in the last few years.  I've previously used Swampfox Optics units such as the Liberty, Justice and Liberator, all of which have since been updated to second-generation versions (follow the links provided for more information).  More recently, I've been mounting Gideon Optics Omega and Advocate units, both for my own use and for a few of my disabled students from earlier times.  I'm also testing two new models from Riton Optics.

As part of the process, I researched the problems some have reported with mounting red dot sights.  Common complaints include (but are not limited to):

• Mounting plates required by some pistols (e.g. Glock MOS, S&W M&P 2.0, etc.) can be too light and flimsy to truly secure the sight to the gun.  Some are even reportedly made of plastic rather than metal.
• Mounting screws for sight to plate, and plate to gun, can be simply too small to maintain their tension, even if thread locker is used.  The G-forces generated as a semi-auto pistol's slide moves back and forth under recoil are very hard on screws at the best of times, and even more so on small screws, which can "back out" under the pressure.  Some gunsmiths specialize in drilling out and re-tapping the relevant holes to take larger screws, but not all of us have access to them, or sufficient funds to allow for such modifications.
• Some lower-cost red dot optics find it difficult to stand up to a heavy diet of rounds.  This applies particularly to competitors, or those who practice and train frequently with their weapons.  For such individuals, cost of optics is secondary to the requirement that they be tough and reliable.  Cheaper sights such as those I mentioned above are simply too cheap to stand up to the treatment they give them.  For the rest of us, who shoot (say) several hundred rounds a year over five to ten range sessions, the lower-cost optics will generally be OK.  If it lasts the first few hundred rounds, it'll probably last the next few thousand!  Also, companies like Swampfox or Gideon warranty their optics, and will repair or replace them free of charge if necessary.

There are answers to the first two problems.  First, mounting plates.  Mass-produced firearms have mass-produced plates, stamped out by machinery designed to do a reasonably good job at an economical price.  They're about what one can expect.  However, there are specialist suppliers out there who put much more time and attention into designing and making the best part they can.  They tend to cost more than the OEM units, but deliver higher quality (at least in my experience).  Two that I've used in the past, and whose products I like, are Apex Tactical and Forward Controls Design.  (I'm sure there are others, whose products may be equally good:  but unless I've tested and used a product myself, I'm not prepared to endorse it.  Shop around and see what you find.)  I suggest that choosing the best plate you can afford is a worthwhile expense.

Second, the mounting process.  Using a thread-locker on the screws (such as Loctite, Permatex, or a competitor) is essential!  I strongly recommend using a gel-type thread-locker, rather than a liquid, for two reasons.  One is to avoid splashes or drips on things you don't want to lock (and believe me, that happens!).  The other is that thread-locker liquid appears to be a perishable substance.  Leave it unused too long and it becomes less effective, to the point that it may no longer serve its purpose.  Gel thread-lockers, in my limited experience, don't appear to have the same problem.  Can any more knowledgeable reader comment on that, please?

Another useful technique helps overcome the limited holding power of smaller screws.  Apply RTV silicone gasket maker, sealant and adhesive to the base of the sight and the base of the mounting plate before installing them on the gun (or directly between gun and sight, if it doesn't use a mounting plate).  That will hold them pretty strongly in its own right, even without the help of the mounting screws.  Be careful not to use too much, or too strong an adhesive, because you will probably want to remove the sight at some point!  I use Permatex 80050, but there are many other brands and varieties out there.  You pays your money and you makes your choice.

One potential problem is that on some firearms (particularly the Glock MOS narrow-slide models, but including a few others), the extractor system is fitted beneath the screw holes used by the red dot sight and/or mounting plate.  If a screw is too long, it can protrude into the space used by the extractor system, and cause problems.  Filing or cutting a small amount off the bottom of the screw (being careful not to interrupt or damage the screw thread) will cure them.  You'll find videos about it on YouTube;  for example, try this one.  If you have a different type of pistol, but the mounting screws can still interfere with internal parts beneath them, the same fix may work for you.

So, there you are.  Sealant-adhesive holding the sight to the mounting plate, and the mounting plate to the gun, plus clean, thread-locked screws, and you shouldn't have a sight come loose just when you need it to be rock-steady.

Peter