Co-Witnessing 101: Iron Sights and Red Dots

Optic co-witnessing lets you use your red dot with your iron sights to improve your tactical flexibility without compromising your reaction time, accuracy, or precision. Unlike many optics installations, which replace the gun’s iron sight usage with just your red dot, this style of mounting keeps your iron sights visible in the sight window, either lined up with your optic’s aiming point or in the lower third of the window, where they are distinct but still usable. Let’s look at why this may be a good choice for your practical firearm optic, and how to make sure you have your co-witnessing dialed in for better shooting.

Why Shooters Choose Co-Witnessing

After spending money on upgraded optics, using your time to install and zero them, and then putting in the range hours getting used to a new sight picture, why would any shooter worry about the stock iron sights on their gun? Just because you’re moving to an upgraded sight picture doesn’t mean traditional iron sights don’t have a lot going for them.

• Familiar – Most of us learned to shoot on iron sights, and even today the vast majority of firearms come with some manner of iron sights pre-installed. The efficiency of habit in a stressful situation shouldn’t be underestimated.
• Reliable – Iron sights are time-tested, provide reasonable accuracy, and are less likely to be affected by environmental conditions. Rain, sleet, or snow, they deliver the bullets to the target.
• No Batteries – Despite advances in battery formulation and power-saving technologies, your optic will eventually need more juice to power its LED emitter. Iron sights don’t blink out from putting a battery change off too long, they don’t dim, and they don’t add an extra expense in the form of spare batteries to stash in your range kit, home gun supply safe, and glove box.

Co-Witnessing Styles

There are two commonly used co-witnessing methods: absolute and lower-third. Each style of co-witnessing offers accuracy and precision through both your red dot optic and iron sights, but their differences give shooters the versatility they need to match their co-witness style to their tactical needs.

• Absolute Co-Witness – This style of co-witnessing lines your aiming point up on the red dot with the iron sights’ aiming point on the front post. As you aim through the optic, you’re able to line up your shot with both at the same time, although the red dot will still function as normal, meaning that within your parallax limit, the reticle lines up with your target wherever it happens to be in your sight window.
  
  Absolute co-witnessing offers straightforward aiming that responds rapidly to changes in lighting and evolving tactical necessities. You aim through a single visual plane that doesn’t require adjusting from one alignment to the other to use either sight. While this installation places the optic closer to the bore axis, you may still need taller iron sights that match the red dot height.
• Lower ⅓ Co-Witness – Moving your co-witnessing to the lower third of your optic window gives you a more open and less-cluttered sight picture. This also lets you straighten your neck some as the visual plane for the red dot sits higher than the iron sights, making holding your sight picture more comfortable. Your optic functions as normal, and lowering your plane to the iron sights brings back the familiar iron-sight picture for quick transitions.
  
  You may need a taller riser for your red dot to line up lower ⅓ co-witnessing properly. Working with two separate visual planes while aiming can also slow down your reaction time when transitioning from one to the other. It’s also worth noting that while this type clears out your red dot sight picture, it can leave your iron sights feeling a bit cramped, especially if your optic uses a larger reticle.

 Zeroing Your Red Dot With Iron Sights

Getting your gun ready for co-witnessing can be challenging if you’ve never used a red dot optic with iron sights before. While the concept sounds fairly simple, a lot of shooters find the practice a bit overwhelming the first time they try to sight through the optic and zero their gun, so let’s take it in steps. 

Install Your Iron Sights and Red Dot

Start by installing and checking the height of your sights together. This means not only mounting your red dot but also swapping out your iron sights if you’re moving to a taller or shorter set. Once they’re mounted together, switch on the red dot and sight through it with the iron sights in your sight picture. Don’t worry about perfect alignment. That comes with zeroing. Right now, you just want the iron sights to be in the general position of alignment with your reticle’s height or the lower ⅓ of your lens.

Zero Your Iron Sights First

At the range, switch off your red dot and start zeroing your iron sights as normal. Make sure they’re locked in on their own so you have reliable accuracy and precision. This also lets you start to get comfortable with the iron sights’ positioning without the reticle getting in the way.

Zero Your Red Dot 

Now it’s time to switch on and zero your red dot. If you’re absolute co-witnessing, use your windage and elevation to position your reticle on the zeroed iron sights and verify your alignment. For lower 1/3, you’ll want to zero your red dot above and potentially a click or two to the side of your iron sights. While this won’t make a large accuracy distance at short ranges, it gives your iron sights a little more spacing from the lowest point of your reticle.

It’s Time to Co-Witness

Once you are comfortable with the zero on your red dot and iron sights individually, it’s time to practice co-witnessing your red dot with your iron sights. Start slow and let your eyes get used to it. The sight picture now has more going on than it did before, but with practice, you’ll be ready to take full advantage of the tactical flexibility in no time. 

Order Your Optics and Accessories Online

When you need cost-effective optics that put rounds on target while keeping more money in your bank account, we’ve got you covered. Shoot better when every shot counts. Order your red dot optics and accessories from Gideon Optics today.