You Don’t Need Them, But You Need Them!
Recoil has the story…
Back-up sights. For every guy who tells us they aren’t needed, there’s somebody else who tells us about the time their brother’s, girlfriend’s, sister’s, boyfriend’s optic took a bullet and he was forced to use his flip-up sights.
We’re still looking for that dude for comment. But, in the meantime, we reached out to three other guys with some verifiable down-range experience and asked them their opinion on back-up iron sights.
J.D. Potynsky is the CEO of Northern Red, LLC and a veteran of the 3rd Special Forces Group. The man has racked up multiple combat deployments and now runs a company that disseminates what he and his teammates learned in combat.
Potynsky recalled one incident when he had to shoot a vehicle speeding toward the checkpoint he was manning. Things went from boring to adrenaline dump quickly and offered Potynsky no time to prepare for the engagement. He raised his rifle to address the threat, but the battery saving feature had shut his EOTech off. With no time to push buttons or flip up the iron sights, Potynsky relied on muscle memory and shot using the window of the lifeless optic and the front sight post on his M4 to hit the vehicle.
“I couldn’t have gotten up a back-up iron sight,” said Potynsky, “there wasn’t enough time.”
But, just as Potynsky explains his one chance to use BUIS was gone before he realized he needed them, he’s also not ready to call them useless.
“There’s an immense amount of pressure to not be that guy,” says Potynsky. “Because if you’re the guy that falls out of the truck on infill and something breaks, it’s irresponsible not to have irons on your gun. Professionals probably wouldn’t go out without them.”
Frank Proctor is the founder of Way of the Gun and an 18-year Army veteran with 11 of them in Special Forces. He spent a couple years teaching the Special Forces Advanced Urban Combat Course.
“I’ve not seen an optic fail. And, I’ve never experienced a failure that could have been fixed by back-up irons,” says Proctor, “It’s just added weight and expense, and I don’t put them on my gun unless I’m only shooting irons.”
But, he knows guys will use them no matter what he says. Whatever sights you choose for BUIS, he says make sure they don’t handicap your ability to use a primary optic. “I’ve seen guys with ACOGs pushed forward to accommodate flip-up irons,” he says, “but that thing should be mounted all the way to the back to be effective.”
On the flipside, Paul Howe, owner of Combat Training and Tactics, an Army special-operations veteran, and a team leader during the 1993 Battle of the Black Sea in Mogadishu, says learning to use irons is essential to competent weapon operation.
“Iron sights have never failed me in combat or on a flat range,” says Howe. While he generally shoots a 3x magnified optic outside of the schoolhouse, he says, “I shoot iron sights when teaching my classes to show students it can be done.”
He also expects his students to run irons and doesn’t give alibi shots if a student’s optic fails during a qualification course of fire. “I expect them to finish the course of fire with their irons,” says Howe, “just like I would expect them to do in a fight for their life.”
All three guys agree that whatever aiming systems you have on the gun, you must practice equally with all of them to be consistent and accurate. So, if you decide to add BUIS to your gun, plan on training with them as if they’re your primary system, so that you’re not fumbling, physically or mentally, when the time comes to go to your back-up sights.
A standard AR sight plane is 2.6 inches above the bore, the height of an M4’s front sight base. Whether rail or barrel mounted, standard height AR/M4 sights line up with this sight plane. Any standard-height sight should work with any other standard-height sight, as well as a standard front sight base. Guns with taller rails, or lower stocks, such as HK 416s and SIG 556s, require shorter sights.
If you’ve heard the term co-witness used to describe sights, it’s likely being used to describe the height of a red-dot sight mount. Absolute co-witness refers to an optic mount that places the reticle in line with the standard AR sight plane. Absolute co-witness irons will obscure the bottom of the optic’s view.
Lower third co-witness refers to an optic mount that places the reticle just above the standard AR sight plane. When looking through an optic mounted with a lower third sight picture, irons occupy a smaller portion of the sight picture beneath the reticle than absolute co-witnessed sights.
Be aware that the multitude of iron sights heights can produce high, absolute, lower third, and even no co-witness with a standard-height optic mount, so pay attention if you’re mixing and matching irons and optic mount heights.
Our advice is to keep things simple when running optics and irons on an AR. You’ve got the best chance of getting what you want if you stick with standard height AR sights and choose an absolute or lower-third co-witness optic mount.
In general, the rear sight of an AR has a rotating aperture leaf. The smaller aperture is usually 0.07 inches and is the go-to aperture for zeroing and normal shooting situations. The larger aperture is 0.2 inches and is useful when you need more situational awareness, such as shooting things up close, movers, or when visibility sucks.
Iron Sight Pictures
We consider the standard sights for an AR to be those found on general-issue military carbines. This is the goal-posted, dual aperture leaf in the rear and a sight post inside a “Y” up front. The most common sight variation you’re likely to see in the USA is the HK-style front sight, which replaces the M4-style front sight arms with rounded arms that many find easier to line up with a round rear aperture.
Beyond the basics, there’s a ton of options for iron sights. Ghost rings and open top sights are at home on shotguns and in cowboy movies, not ARs. Modern rear sights can have round, square, diamond-shaped apertures with any number of things going on around them to help speed up sight alignment including, painted lines, barbs, and tritium inserts. Up front you can find white and colored sight posts, chevron markings, fiber optic and tritium inserts, and plenty of other useful and useless novelties.
Inline or Offset
Far from the last consideration when it comes to irons, but the last one we’ve got room to cover, is inline or offset. Running a flattop rifle with an unmagnified (red-dot) optic? Take your pick. This combination allows the use of inline BUIS with the primary optic still in place, as long as a lens isn’t smashed or fogged up. If you’ve got a QD optic mount, you’re still in business with an obscured optic. If not, you better hope you’ve got a wrench, or offset irons.
Offset irons are great as a back-up for a magnified optic and as a second set of sights for targets too close for the primary optic. Roll the rifle so the sights are plumb to the bore and carry on. Precision guys without a Pic rail, don’t feel left out; we’ve got offsets that mount directly on your scope tube.
When it comes down to it, it’s on you to decide if saving 4 ounces is worth the risk of being thatguy.