Red dot sights on pistols are becoming increasingly prevalent. They are not a new concept, however. Shooters like Jerry Barnhart started entering IPSC competitions with red dots mounted to pistols in the early 1990s. These early optics were actually rifle red dots retrofitted to pistols and were sometimes over a pound in weight, far greater than the different red dot optics we’re seeing on pistols today.
In the early days, gunsmiths had to experiment with different ways to mount optics to pistols. There are still different ways to do it today, but the process is generally limited to a few different options. Some handguns come from the factory ready to accept an optic through various plate systems such as the Glock Modular Optic System. If your pistol isn’t, you can have your slide modified for one; optic-ready aftermarket slides are also becoming more common.
Some shooters still utilize iron sight dovetail mounts or other brackets, but these are now considered outdated by many because of their weight and awkwardness.
Mounting a Red Dot Sight
The most common way to mount a red dot on a pistol is to have the slide machined for a specific optic. This is the method recommended by most gunsmiths for several reasons, the biggest being a precise fit. Optics will vary in dimensions, even when comparing two examples of the exact same model. Differences as little as 1/1000 of an inch can influence how the optic fits to the slide.
A good gunsmith will measure and cut a slide to exactly match a provided optic, removing any chance of play between the optic and slide due to manufacturing tolerances. Having an existing slide cut for a red dot is also usually the most affordable option as well. Machine shops generally charge between $100 and $400 to perform an optics cut, depending on the different options and services available.
Not everybody has the funds to go out and buy a new handgun or slide in order to run a red dot. It should be noted these optics cuts are permanent modifications to the handgun and will likely void any warranties provided by the manufacturer.
It’s also important to choose a competent gunsmith, as some of these cuts can interfere with the function of internal parts, such as safeties or extractor plungers, if machined too deep. If done incorrectly, milling out a slide can severely weaken the metal in a slide which can lead to catastrophic failure of the firearm – It cannot be stressed enough to choose a reputable machine shop to do this work.
When having your slide milled, it’s possible to have additional machine work done such as front or top serrations and windows. Another thing to consider when having a slide milled is you’re pretty much stuck with whatever optics footprint you chose for your gun. Many optics share the same footprint, but there are a few major footprint designs out there that aren’t compatible with each other.
When handgun manufacturers realized mounting red dots on handguns is the way of the future, they started offering factory optics-ready options. Glock, for instance, came out with the Modular Optic System, or MOS. This system comes pre-machined from the factory and includes a series of different mounting plates so users can switch between different optics.
The ability to switch between different optic footprints is huge but does not come without drawbacks. When using these plate systems, the optic generally sits much higher than with custom options due to the thickness of the plates, so it might be more difficult to co-witness iron sights to your red dot.
Factory options like the MOS system generally aren’t as sturdy as custom options either, as the optic is contacting the plate instead of the actual slide, making it a potential failure point. Competition shooters have complained of optics and plates working themselves loose after a days’ worth of shooting. Going with an OEM option, however, carries the benefit of a manufacturer’s warranty and you won’t need to worry about the possibility of your slide cracking due to poor workmanship.
Since factory optics-ready pistols don’t require any permanent modifications, they will usually hold their resale value better than custom guns, depending on who did the machine work. This route, of course, requires you to purchase a separate firearm in order to use a red dot optic, but this could be seen as either an advantage or disadvantage since two guns are always better than one.
If you’re not comfortable with making permanent modifications to your slide and don’t want to spend the money on a whole new firearm, aftermarket slides might be an option to consider. Many companies now offer aftermarket slides, especially for the Glock platform.
You can keep your factory slide original and still have the ability to run a red dot. The quality of aftermarket slides can vary as much as the different levels of workmanship found in custom machined slides, though. Some aftermarket slides might be cheap and unbranded, while others can be made of rare and exotic metals, like Lone Wolf’s Damascus steel slide which retails for $1,499.99.
As we’re in the age of the “Gucci Glock,” how your gun appears can be perceived as just as important as how it shoots. In addition to adding optics capability to your gun, aftermarket slides can come in many different designs and colors that go further than your basic slide serrations, windows and lightening cuts typically found on customized factory slides. Again, like having your slide cut, you must do research on who manufactures your slide in order to choose a reputable brand.
Companies like Brownells make affordable slide options but are often only cut for one style of red dot footprint. The more affordable aftermarket options also might not be as flashy or cool looking as custom slides. For people that want an OEM look without modifying their factory slide, a few companies now offer aftermarket slides with a profile identical to factory slides.
It’s Your Choice
While having a slide custom cut for your red dot is probably the most popular and recommended option, everybody has different requirements for their gun. Regardless of the route you take, it’s important you go out and train with your gun and optic.
Even professional shooters might have trouble shooting with a pistol red dot, or a laser sight, after years of shooting iron sights only, as there is definitely a learning curve for some people. New or inexperienced shooters tend to “chase the dot” when it bounces around from recoil.
Furthermore, you’re going to want to put a decent number of rounds through your pistol to make sure your slide and optic are able to withstand the proper amount of abuse. Once proficient though, pistol mounted optics can boost a shooter’s skill in both speed and distance shooting.