Some shooters just don’t cover the distance that would necessitate a scope. One of the perfect close-quarters combinations is the red dot sight and the flip-up magnifier. While many people go this route, few will take the time to properly align their optics, which can cost accuracy. Here’s how to correctly align your magnifier with your red dot.
Four Steps To Align Your Magnifier & Red Dot
While this doesn’t seem like a complicated process initially, there is a lot of room for over or under adjustment. Getting the height correct can be challenging, depending on your assortment of shims, and getting it all zeroed can be a task. Be sure you have several shim options on hand so that if either attachment needs adjustment you have options. Here are the basic steps to aligning your magnifier and red dot.
1. Ensure The Magnifier & Mount Are Assembled Correctly
One of the biggest chances for misalignment or difficulty in alignment is the magnifier not being correctly attached to its base. Whether the magnifier is fixed or flip-up, it should be correctly assembled ahead of time. Your red dot may be set to absolute co-witness, or lower ⅓ co-witness, which will ultimately determine how much you’ll need to shim your magnifier to be aligned.
Having the base not fully aligned or attached can lead to significant mounting issues. Trying to align a magnifier that has the potential to shift or change alignment is a recipe for disaster. Your magnifier and red dot sight should both be rock solid and unable to move or shift once installed, otherwise ten rounds in you’ll be stopping to realign again.
2. Your Height Will Be Determined By The Height Of The Shims
The basic method of height adjustment for pistol and rifle attachments is shimming. They are flat pieces of steel that are machined to exact tolerances to provide changes in height for attachments. Since you cannot lower anything beyond the frame of the gun, you will need to figure out how to align your red dot and your magnifier by either adding or taking away the shims.
You may be able to find shims made from both metal and plastic. While plastic shims may sound less capable, they can stand up to rigorous use just as steel shims can. In some cases, plastic shims may even be preferable, since they won’t add the additional weight that metal shims will, which isn’t much but it’s still more than zero.
While many magnifiers come with a shim or two to ensure a more universal fit, they won’t always be the ones you need. This means that you should have a small assortment of shims and shim screws on hand for last-minute adjustments. In many cases, you’ll be at the range trying to zero your red dot and align your magnifier, so it’s best to have those things nearby when you may potentially need them.
3. Shim & Adjust Until The Red Dot Matches The Magnifier
In most cases, you will already have your red dot or holographic sight zeroed, which will make matching the two significantly easier. If your red dot sight is already zeroed, for example, and you check the alignment of the magnifier without any shims and see the dot in the upper ⅓ of the optic, you know you’ll need to add a shim to the magnifier.
Shims are available in different sizes, the different thicknesses of each being measured in degrees. The most common shim thickness is 1 degree, though fractional shims are available for micro-adjustments just as shims greater than a degree can be used to gain more ground.
One thing to think about if you need to use larger or smaller shims is the eventual need for screws that match the size. If you are using a shim that is 2 degrees, you will need a significantly longer screw than for one that doesn’t need a full degree. This is important since it can be a difference of a millimeter or more depending on the size of the shims and the firearm’s specifics.
Be sure that before you fully tighten down the magnifier, you double-check the magnifier's direction of swing. When you are holding the firearm, you’ll want the optics to swing out of the way in a particular direction to be effective. Too many shooters realize long after the fact, that they forgot to change around the base and now their magnifier flips out of the way in the wrong direction.
4. The Only Distance That Matters Is Eye Relief
Many shooters wonder if there is an ideal distance back from the red dot or holographic sight that they should mount their magnifier to be most effective. The first thing to think about is the eye relief on your red dot or holographic sight since you won’t want to mount inside of that distance. However, as long as you’re outside that distance, your magnifier should be able to provide a clear, fixed magnification image of exactly what you would see in your optics.
There is no predetermined distance or position that your magnifier will need to be behind your red dot. The biggest concern should be where it should be mounted to achieve optimal eye relief. In most cases, the sweet spot will be relatively generous, but you will want to ensure that when you’re shooting you are seeing the optimal sight picture.
One thing to consider when choosing where your magnifier will mount is if you will be using a quick disconnect or quick dismount base. If this is the case, your magnifier will be using a quick detach function, be sure that you have that base fully torqued down after adjustment and alignment before you use the gun.
For most applications and firearms, 20 inch-pounds is just about perfect. Any more than that and you may start to create stress warping, and any less than that may see the screws and attachments loosen up over time.