A.R.M.S. #71L Series, Rear Sight - Polymer BUIS
- Designed to allow attachment to all Universal Dovetail 1913 and Weaver style Rails.
- Both are made from durable, metal-reinforced polymer and are a good option when seeking a quality sight.
- Both are .610" when in the folded position, from the top of the receiver.
The Sight is rail mounted with a quick deploy latch and adjustable for elevation and features the same metal dual apertures, utilized in the A.R.M.S. #40L under contract with Crane Naval Special Warfare Center, for both CQB and long range shooting applications.
- AR 15 sights
- arms flip up sights
- best backup iron sight
- Polymer BUIS
The distinction between inferior quality and premium AR-15 Rear Sight is undeniable. At MSP, we only offer AR Accessories from the most trusted brands like ARMS Sights. Buy with confidence that we stand behind the product we sell.
Customer Ratings & Reviews
Good backup iron sights with one exception
These back up iron sights came with my Rock River LAR-15 Operator III. The sights are pretty good, with one exception. When the sights are released, they bounce back a little from their fully upright position. This is especially true for my rear AR-15 sight. After releasing them, you need to push them into their full upright position. Doing so gave me excellent repeatability after firing a few rounds, collapsing the sights, and then re-releasing them again and firing a few more rounds. Releasing the sights and not taking a moment to push them into their fully upright position will leave you with erratic groupings since the sights don't deploy to their optimal position by simply pressing the release button.
best backup iron sight
These are excellent polymer BUIS. These sights are sturdy and hold their zero. The front view can take a replacement post if so desired. I’ve shot mine out to 300 yards with no issues. They weigh virtually nothing. They are cost-effective, and, yeah, I have experience with the other polymer BUIS, and those other ones are cheaper for a reason. I keep coming back to the 71L. Take note that the reviewers who complain about the rearward cant need to do their homework: the cant is designed into the AR sights so that they will press backward without breaking if the gun is shoved into an obstruction. This is a positive and not a negative! Also, the negative reviews who acknowledge they received counterfeits are just stupid— rate the real product, not the counterfeit, please.
Best BUIS sight
I have been using these AR-15 B.U.I.S. sights for the last few months now and couldn't be happier with them. For the money, they are absolutely the best sights on the market, and although Magpul's M.B.U.S. sights (with which I am thoroughly unimpressed) get all the press, these are far superior. The rear AR-15 sight has the standard large & small apertures of course, but they also incorporate a sighting notch on the top of the aperture that can be used both the extreme close range shooting to compensate for the sight offset as well as at long range to compensate for bullet drop. It is essentially a lower-priced polymer version of A.R.M.S.'s #41-L low profile B.U.I.S. I highly recommend them!
The ARMS 71l flip up AR-15 sights do the job as backup sights
The ARMS 71l flip up AR-15 sights do the job as backup sights, would not want to depend on them as primary sight. They seem canted front to rear like they don't open entirely but they do zero so I guess there's that. They work, and they are ok thus the 4 star rating.
Perfect Back Up Sights on a Budget
So I know these are not Magpul, Midwest Industries, Daniel Defense, or Troy, but these work just as well. With the age of red dots, holographic, and reflex sights, the iron sights have become known as backup sights or BUS. ARMS has done an excellent job of getting a functional set of Flip up AR-15 sights that I like better than the Magpul ones. These are polymer sights, so they are light. The rear sights have two peepholes. They "pop" up quickly, and the adjustable knobs are work smoothly. I have this installed with the VLTOR CASV rail, and the rear BUS works great with it. I gave 4 stars because they need to make these in other colors. (Former US Army)
Great price for an excellent AR-15 Sights!
The title says it all. You can't find a better price for quality BUIS such as these A.R.M.S. Rear AR-15 Sights. They are polymer, which I like, but just don't mount the front sight to the gas block. The rear sight has 2 apertures (1 for day and 1 for night), and is easy to adjust for windage. These sights are a little bulky, but other than that, I love them.
Great price but big foot print.
These rear AR-15 sights are not to bad. Comparable to Magpul BUIS. However, these sights need a large mounting space. The rear unit doesn't go to the end of the back of the AR-15 top rail. It mounts forward of the standard mount location, taking up more rail space. These are also made of plastic. No adjustment issues, so far, this work. Just big. I'm using them on a LRT/SASS in 7.62
#71L Rear Sight
Seems strong enough but it pops up when I am not wanting it sometimes when I am working the action. It is real easy to hit accidentally. I like the old metal version better because you have to flip the metal lever back to unlatch it.