Red dot sights are not the future of shooting, but are rather the current tech. However, you should still have back up iron sights (BUIS) on your defensive handgun. While we are in an era of high quality dots, the durability is not quite good enough to be able to forgo a set of irons on the gun. This leads to the question, where should you put the irons?
Why Should We Have Irons On Our RDS Pistol?
Red dot sights have gotten quite durable. In my experience, the Trijicon RMR and Aimpoint ACRO P1/P2 are the most durable, however, we still need a back up aiming solution. Rifle red dots are considerably more durable than handgun optics, and are not generally subject to the same forces that a handgun will have. Your pistol optic has to endure reciprocation, and lots of G's when being used, and as such, can fail more frequently. With this in mind, we've got the need for BUIS.
So where do we put the irons on the gun? The front sight will obviously stay at the front of the slide, but how about the rear sight? Well, there are two common spots, behind the optic, and in front of it. What are the pros and cons to each?
Pros of Irons Behind The Optic
The most common spot that you see the rear sight is behind the optic. Most OEM optic ready guns have the rear right here, and it makes sense. On iron sight only guns, the rear sight is all of the way at the rear of the slide to have maximum sight radius, and it's easier for companies to just mill a spot for the optic in front of the sight. For this location, I see three main benefits of this rear sight location;
- Longer sight radius
- Lower cost
- Better concealment (less printing)
First and foremost, this position offers the longest sight radius. At this position, we've (generally) got the biggest space between front and rear sight, which gives us the best precision with the sights. I don't personally find this super important, as shooting with a shorter sight radius doesn't impact self defense/combat accuracy at a ton. Nevertheless, the increased sight radius is a benefit.
Secondly, this position is cheaper. The dovetail is already in the gun, so we aren't spending more money to relocate the rear sight.
Lastly, this sight location generally offers better concealment. This will vary from gun to gun, person to person, and holster to holster, however, the gun will usually print less with this position.
I do think that there are some cons here too.
Cons of Irons Behind The Optic
There are two distinct downsides to the traditional, iron sight behind the optic position:
- Less protection for the optic
- A busier sight picture
With having the rear sight behind the optic, the optic is pushed further forward on the slide. With the optic moving closer to the ejection port, that opens up to a few issues. Notably, if we need to rack the slide using one hand, we're using the optic. While the optic is durable, it isn't without failing. We could break the optic if it is crappy, or impact our zero if the force causes the mounting screws to move. On top of that, our glass is going to be taking some force from spalling, blowback, and carbon fouling. On my EDC X9, getting carbon fouling from the ejection port is a common occurrence.
In this configuration, we've also got a busier sight picture. We've got rear sight-optic-front sight as our viewing order, which can seem busy for a lot of people. I've shot a myriad of guns with optics over the years, so I don't find it all that distracting. However, I've heard from many shooters of varying skill levels who state that they find this layout a little harsh on the eyes.
For some, this may be a deal breaker, for others, it's nearly a non-issue. How about the rear sight forward position?
Cons of Irons In Front Of The Optic
Our other position is irons in front of the optic. I see a few downsides to this position, but I think the upsides are worth it:
- Costs more money to mill a new dovetail
- Shorter sight radius
- Can negatively impact concealment and printing
No mincing words, it costs some dosh to mill a new dovetail for the rear sight. On my three milled guns with forward dovetails, that extra work cost about $30 each.
We do have a shorter sight radius, generally losing about 1.5-2" of sight radius. I'd argue that this doesn't really make much of a difference, however, it is a slight downslide.
For some people, concealing a gun with this sight orientation might be worse. With putting the optic rearward, this might print a lot worse for you. A good holster and clothing selection can help change this however.
While these might sound like big downsides, they don't make a real negative change. The upsides are really, really worth it.
Pros of Irons Forward
Now, for those three downsides, we gain two major upsides:
- The optic is protected by the rear sight
- The sight picture is less busy
With having the rear sight in front of the optic, we are protecting the glass of the optic. Whether it be using the iron to rack the slide one handed, or protect the glass from spalling/carbon fouling, we're able to better keep the primary aiming solution safe.
In addition to keeping the optic protected, we've now made the sight picture less busy. Rather than having the orientation of rear-optic-front, we've got optic-rear-front. This method makes the sight picture a little easier on the eyes, and for many shooters, easier to use. I don't find this to be a massive improvement, but I've been shooting RDS handguns for years. Newer or less experienced shooters tend to find a bigger benefit here.
I am totally content with using pistols with rear sights in either position. I've carried guns with both, and currently own an even split of rearward and forward mounted rear sights. I've also been shooting RDS handguns for several years, so some of the upsides or downsides might not impact me as much as they may impact you.
However, if given a choice, I do prefer the rear sight in front of the optic. For me, having the iron sight as a protector for the optic has been an immensely life-improving thing. I've had better luck with avoiding optic damage and fouling, and slightly better fitment in certain holsters. The benefit of a simpler sight picture is nice too, but I've not found that to be as beneficial as the protective factor. But again, I'm still content carrying guns with either rear sight location.
I recorded a video to show some more details, and that is available below.
Regardless of the position of your rear sight, the important thing is that you've got BUIS on the gun. I've got my preference on location, but hey, it's just a preference. What do you prefer?