How Does the Echelon Variable Interface System Optic Mount Work?

By Justin Opinion

The Springfield Armory Echelon introduced a new optic mounting system that is revolutionizing how you add a red dot to handguns. Called the Variable Interface System, this ingenious bit of engineering allows you to direct mount most popular pistol-sized reflex sights made today.

Eliminating adaptor plates for most optics brings the sight closer in line with the muzzle while also reducing a point of failure. For the few sight mounting patterns that are not natively supported, an adaptor plate can also be used. In this article, Justin Opinion takes a look at the Echelon Variable Interface System optics mount.

Optics on handguns, particularly small electronic sights, or “red-dot sights”, have become almost as commonplace as iron sights in the past few years. Just a decade ago, mounting a red-dot on your pistol was an expensive commitment that often meant specialty cutting by a gunsmith or machinist, or required an elaborate adapter that was sometimes fastened to the frame of the gun. It was not really a long time ago, but it is a long way from where we are today — for the most part.

As the technology and popularity of electronic optics progressed, what failed to keep pace was a standard mounting pattern. To my mind, it seems like the red-dot manufacturers must have been influenced by Cheech & Chong’s iconic movie “Up in Smoke”, and thought the line, “Hey man, if we’re going to wear uniforms, man, you know, let’s everybody wear something different.”, would make a great industry strategy. And so it has been for years — we live in a world of adapter plates, differently sized screws, and outright incompatibility.

Variable Interface System: The Universal Key

Springfield Armory, with the introduction of the new Echelon, is making life much easier — and less expensive — for red-dot users. How? With their new Variable Interface System. Instead of bulky and often costly adapter plates, the Echelon Variable Interface System uses sets of self-locking pins to fit the patterns of an extremely wide range of popular red dots. In all, over 30 different optics can be mounted to the Echelon without having to buy anything extra.

The Variable Interface System is designed to work directly with the Trijicon RMR, Leupold DeltaPoint Pro and Shield footprints (and all the associated matching footprint optics). However, Springfield offers plate systems for the Aimpoint ACRO and Docter footprints, which require a larger foorprint area. This was done to allow for the widest range of options for the pistol.

Changing optics from one footprint configuration to another on the Echelon is quite simple. However, the pins are fairly small — so I have found that using a simple tweezer (stolen from a bathroom drawer, for which I will probably be in trouble) is a great way to handle the pins and set them into place.

Three different pin sets are provided in the box with your new Echelon, and between them, you can mount just about any optic you wish to use. Springfield Armory also provides a very handy compatibility list that tells you exactly which pin set to use for which brand and model optic.

Pin set #1 is already in the slide with a new Echelon, and it is the set you’ll use for RMR footprint optics as well as the cover plate when you go sans red-dot. It consists of only the two front pins, whereas pin set #2, which is for the DeltaPoint Pro (DPP) footprint, and set #3 for the Shield footprint each use four.

The self-locking pins do much more than just make our lives simpler — as if that wasn’t enough. The pins are designed in such a way that when properly installed, and the optic is fastened to correct torque, they push outward inside the locating holes of the optic with just enough pressure to hold it firmly in place against side-to-side movement. For the technical among you, this is like having an interference fit that you can still slip on and off easily. For the rest of us, it just means a more stable mount with a much more reliable zero.

Variable Interface System In Practice

Installing the pins to fit your specific optic to the Echelon is a piece of cake. Once you remove the cover plate or the optic that is already on the gun, simply pluck out the pins from the mounting holes and carefully store them away. The pin sets as provided come in small zip-lock bags which are labeled, except for Set #1 — and I simply added a third bag and labelled it myself with a Sharpie. Organized and properly stored parts is rule number one!

The front pins of sets two and three are specific to the side to which they are installed — they are marked “L” and “R” accordingly. As you can imagine, that stamp is very small and if your eyes are like mine, you might need a magnifier! This is important to get correct, because they are shaped to provide the lateral locking and proper fit.

Place the teardrop shaped pins into the teardrop shaped front holes with the flat side down. The raised “post” side with the marking for left and right should always be at the top. The rear pins are less complicated but do have a difference in diameter between top and bottom, so the orientation is also important for them — larger diameter faces up. Those are really the only rules to remember when swapping out the pins. It’s that simple — and you’re done!

Final Thoughts on the Echelon’s Optics Mount

There are a number of advantages to the Variable Interface System, for both the end user and the manufacturer. For Springfield Armory, I think it makes good sense to allow maximum optics compatibility right out of the box, and the pins are likely an inexpensive accessory to mass produce, compared to quality adapter plates. In fact, you can purchase the full set of pins from Springfield for under $20. I’ve seen companies that charge significantly more than that for a single adapter plate.

And for the consumer, that same low cost of manufacturing shows in the retail price of the gun. You’re not paying for five adapters that you might not ever use, or having to pony up $30 for the one you need. The Variable Interface System is designed to mount a wide range of optics without any increase in the height of the optic. Better co-witnessing with open sights and a more stable connection with a truer zero — what’s not to love?

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