Springfield Armory follows Glock in offering the Aimpoint COA pistol optic with the A-CUT mounting system direct from the factory. Will this become the new standard for pistol mounted optics?
by Rob Reaser
Pistol Mounted Optics are here to stay. Anyone who questions that should probably crawl out from under their rock. Once you become accustomed to PMOs and get your presentation up to speed, you’ll quickly acknowledge their benefits. Handgun manufacturers have seen the writing on the wall and have accepted that producing slides that are ready to receive optics is pretty much demanded by today’s consumers.
But there’s a problem, Houston. And it’s been plaguing us for far too long.
At Shoot ON, we deal with the problem ALL THE TIME, and it is beyond annoying. We keep a couple handfuls of various red dots on the shelf to do our handgun evaluations. As most of you who run pistol optics know, the mounting footprint can and does vary between optic manufacturers. The most common footprints are RMR, Shield RMSc, Delta Point Pro, Docter/Noblex, and Aimpoint Acro. There are more, but you get the idea.
Usually, we can find an optic that offers a direct mount to the test gun’s slide. You see, pistols can come from the factory with a specific optic footprint. These variants are annoying because the range of red dots you can use on them is often limited.
Five different pistol optics, five different mounting footprints. This needs to stop.There are, fortunately, workarounds in the form of adapters offered by various aftermarket manufacturers. These adapters allow you to mix-and-match footprints so that you can put an optic with footprint “A” onto a slide cut for footprint “B.” Some pistol manufacturers even have their own proprietary slide cut footprint that utilizes mounting plates (included with the gun), allowing you to use a broad range of optics with different footprints.
Is that a good solution? Well, it works, but it is certainly not optimal. Adapter plates add an extra layer of complication to the gun, minor though it may be. You are adding weight to the handgun, and you are raising the optic to a height that may not allow co-witnessing of or functional visibility of the factory open sights (you want those backup sights!). Furthermore, we’ve found in our years of testing that not all slides, adapters, and optics offer consistent dimensions. We’ve installed numerous optics that are ill-fitting and “gappy” due to tolerance stacking.
Every time I get in a twist because of poor-fitting adapters or an inability to expertly match a specific optic to a specific gun, one thing screams in my mind:
“Why won’t this industry get it together and come up with a standard?!”
We saw this over the last decade with the whole M-LOK vs. KeyMod accessory mounting thing. Eventually, an industry-accepted standard comes forth and smiles bloom all around. In this case, M-LOK emerged victorious. The HUB (Hybrid Universal Base) mounting system is another recent example of a standard being adopted by the major suppressor manufacturers to make life more convenient for the end user when it comes to mixing and matching gear.
That hasn’t happened yet with the ongoing hassle of handgun/optic footprints.
But maybe…just maybe, the battle royale — the “there can be only one” moment — is on the horizon.
In January 2025, Glock and Aimpoint announced a collaboration whereby the storied pistol manufacturer was given a one-year exclusive to produce and sell as a factory package several models (G43X, G48, G19 Gen5, G47, and the G45) with the new Aimpoint COA optic. The big deal here is that the COA utilizes an all-new footprint called the A-CUT.
Someone must be “first out” in such matters. Aimpoint developed the COA and A-CUT mounting pattern, but it required one of the halo pistol manufacturers to effectively bring it to market. So, Glock stepped up to be the first horse in the rodeo. The two companies locked arms, so to speak, and the COA/A-CUT system hit the scene in late January 2025.
Fast-forward a year later and the COA/A-CUT momentum is building rapidly. The Glock-exclusive on offering the COA and A-CUT pattern pistol package has ended and the next chute is opening up.
A January press release from Aimpoint explains:
“During the NSSF SHOT Show, Aimpoint announces a significant expansion of its COA® pistol red dot sight through a growing network of OEM partners. The COA optic is offered as a factory-installed package, with pistols shipping directly from manufacturers equipped with the optic via Aimpoint’s integrated A-CUT® interface.
This expansion represents a major step forward in Aimpoint’s strategy to redefine the standard for pistol-mounted optics. By offering a direct-mount solution engineered specifically for duty-grade performance, the A-CUT system delivers enhanced durability, consistency, and performance for professional and civilian end users alike.
Aimpoint has licensed the use of the A-CUT with major firearm and accessory manufacturers, including many of the most prominent handgun manufacturers in the market. Additional factory-installed pistol and COA combinations are planned throughout the year, reinforcing Aimpoint’s objective to establish A-CUT as the industry standard for optic mounting on pistols.”
Who is the next pistol manufacturer to step up?
Springfield Armory.
Today, Springfield released their first handgun to be sold with the Aimpoint COA and A-CUT slide configuration. The company selected their popular Echelon series to host this debut, but our friends at Springfield told us that they will also be offering the COA package with their 1911 variants and 1911 DS Prodigy models in the future.
We have reviewed the Echelon series quite extensively here at Shoot ON, covering the Echelon 4.0C, the Echelon 4.5F Comp, and the Echelon 4.5F, so there’s no need for another deep-dive. Check out these links if you want to read about our hands-on evaluations. What we want to do here is let you know that the Echelon is now available from the factory with the new A-CUT slide cut and Aimpoint COA and give you a close-up of what this new system is all about.
Those of you who are familiar with a variety of optic slide cuts can see right away that the A-CUT is different from what you’re accustomed to. There are no pins or screw holes in the cut. The forward ledge is angled like a dovetail while the rear edge is perpendicular. Grooves are cut along each side. The base of the COA optic follows this same pattern. This positions the front of the optic in the half-dovetail and prevents any fore/aft movement of the optic. Lateral movement is arrested by the parallel grooves in the slide.
Locking the optic into the A-CUT is the rear sight plate. The slide is cut, drilled, and tapped to accept the sight plate and two retaining screws.
When installed, the front of the sight plate overrides the rear wedge of the COA, effectively locking the assembly in place.
There are a couple of real advantages to this design.
First, the fore and aft recoil forces are placed on the front and rear of the slide cut. On conventional optic footprints, there can be significant recoil force placed on the retaining screws or pins, depending on the design, which could cause the attaching hardware to shear.
Second, this system allows for extremely low mounting of the optic, providing a short sight-to-bore relationship and ensuring front/rear sight visibility through the lenses without the need for taller sights.
Overall, this system makes a lot of sense because it is an exceptionally stable mounting solution and uncomplicated in its design. No adapter plates, no pins, and no multiple screw sets to secure the optic in place. It’s strong, and it’s easy to install.
The question is, will optic manufacturers agree and decide this is the way to go? Only time will tell. What we do know is that Springfield Armory will be rolling out additional models with the A-CUT, and other gun manufacturers are jumping on board. Smith & Wesson had an M&P 2.0 on display at SHOT sporting the A-CUT and COA optic. There may have been others that we missed.
On the support side, our friends at XS Sights have already come out with their top-selling R3D 2.0 tritium sights for select A-CUT Glock models with the COA optic.
For now, Springfield is offering the Aimpoint COA with the A-CUT slide in three Echelon models: the Echelon 4.5F COA, Echelon 4.0C COA, and Echelon 4.0FC COA. And as we mentioned earlier, these will be followed by 1911 and 1911 DS Prodigy variants with this same optic package, so stay tuned.
