First Impressions – Aimpoint’s COA and Glock’s A-Cut

For as long as we’ve been mounting miniaturized optics on pistol slides, there have been debates over the mounting footprints. Several designs have come and gone, while a few have established themselves across multiple manufacturers. Many have voiced a hope that the firearms and optics industries would unite and standardize on just a few footprints, paving the way for a more streamlined and efficient future.

Three of those currently stand out as being common enough to be called “industry standard.” They are Trijicon’s RMR pattern, Ruggedized Miniature Sight-Compact (RMSc) designed for narrower concealed carry slides, and Aimpoint’s Acro. The RMR and RMSc are both bolt down into the slide patterns, and numerous manufacturers use them.  The Acro essentially bolts across a base that looks similar to the M1913 Picatinny standard rail. My last count shows eight other companies make and sell optics fitting the Acro footprint. Yes, there have been and are others, but none are as common as these.

Whispers

About a year ago, rumors began about a new pistol optic from Aimpoint. Nothing solid. As ’24 went on, I heard them more frequently, but little was being shared. Both NDAs (non-disclosure agreements) and what some jokingly refer to as FriendDAs—sorry, bud, can’t share—were working. There was some thought that Aimpoint might be coming out with a narrower Acro for slides like those on the M&P Shield and G48, among others.

Collaboration

Then, very shortly before SHOT, Aimpoint and Glock announced the result of their joint project—the A-Cut footprint and COA optic. As we now know, it was not a narrower Acro. It is a different optic with a much different footprint. And, at least for now, it can only be found on Glock pistols cut for that footprint. For the rest of 2025, the COA and its base are restricted to Glock pistols.

Sheered Screws

One of the continuing concerns about pistol-mounted optics has been mounting failures that include screws sheering. That has been happening with both plates and the optics – even when plates are not used.

The COA’s base greatly minimizes that because of how it locks the optics into the cut. Where the two screws are – in a rear clamping piece – should mitigate that as well.

Aimpoint and Glock appear to have cooperated on the footprint design. They call this mounting solution the A-Cut.

The forward edge of the cut is angled backward. To seat the optic, its front edge goes into that forward edge before you seat it by moving the body rearward and down. Both sides of the slide cut have channels that run front to back on the outside of it. Once the optic is seated, the rearward clamping piece then secures the optic in place. It utilizes two larger screws to bolt that piece downward into the slide. These screws are significantly larger than any others I have used with “bolt down into” optics.

This rear clamping piece doubles as the rear back-up iron sight (BUIS). By doing so, an already shorter overall length optic now sits further back, which will mitigate debris accumulation on the front lens.

The Optic

So, it’s a dot. Yes. It has an enclosed emitter design, which I prefer for any role in which the pistol is openly carried. The reticle is a 3.5 minute-of-angle (MOA) dot. It is powered by a CR2032 battery with a reported 50,000-hour life. The battery tray is now inside the sight’s body. Also, the tray has a thicker screw. Some existing enclosed emitter designs have had issues with humidity inside the housing. COA’s design uses the battery tray itself as the sealing mechanism.

While I handled a few Aimpoint COA-equipped Glocks at SHOT, I hadn’t been able to shoot one until very recently. Wayne Dobbs is one of Aimpoint’s law enforcement representatives and a phenomenal teacher. I helped him out with an introductory PMO class at a training conference. Dobbs was demonstrating with an Aimpoint/Glock COA pistol and had others with him. I managed to squeeze in (pun intended) a few magazines with a COA-mounted Glock-19.

This sample does not constitute a review. Rather, it is a first look, an initial impression.

Controls

The brightness up and down controls were easy to manipulate without being so large they could be inadvertently adjusted. It is night vision compatible, with four NVG settings and eight visible ones.

Size

The COA is visibly smaller nearly all the way around. While the thickness of the Acro’s housing wasn’t bothersome for me, the COA’s thinner walls were noticeable. That makes some people happy.

There is just one size of COA, and it fits both slim and full-width slides. Complete Glock pistols (19, 43, 45, 47, and 48) are available for sale with the COA.

Back-Up Iron Sights

I shot it on a B8 repair and the head of a PSL silhouette target at 7 and 10 yards, respectively. There was no issue with acquisition or tracking, though I cannot tell you the brightness level. Accuracy was acceptable. Hits on the repair center were in the black. As for the headshots, Wayne had placed a lateral post-it note on it. While my first two shots were just under the note, when I asked, Wayne said it was a 2″ group, laterally centered. I mention that because there has already been discussion about the rear sights on the clamp not being adjustable. At that distance, for those shoots, the lack of adjustment was not an issue.

Final Thoughts

Admittedly, I have a bias towards Aimpoint – I once worked for them. The mounting solution is a leap forward – hopefully, other manufacturers will adopt it; two companies I specifically asked about are addressing that now. While I have several pistols cut for various direct mount footprints, in the future, this could greatly simplify things for all. It would also positively impact mounting failure concerns.

I am looking forward to getting much more time on the COA, regardless of the pistol. To purchase these now, check with your local Glock L/E dealer.