Iron sights are the most reliable sighting system because they don’t run on batteries and don’t contain moving parts. I have been looking for an iron sight for a long time and I came across the Magpul MBUS. 

In a recent KitUp article, three name-brand sights were tested on a .300 AAC Blackout AR-15. The rifle was then dropped upside down intentionally to hit the rear back up sight to see how far the sight went off its preset zero. The results were as follows:

The first BUIS dropped was the Diamondhead. At first, damage appeared cosmetic only; however, the apertures could no longer be rotated, windage could not be adjusted, and there was a definite cant to the BUIS. Point of impact shifted approximately 16 MOA. We contacted Diamondhead with this result. They replied that a newer version was available which was more durable. We offered to test the new model but production issues meant they could not ship one to us.

 Next came the Troy sight. Cosmetic damage was apparent, but the sight could still be operated normally. Point of impact shift was approximately 3 MOA.

The last set of BUIS was the Magpul MBUS. Damage was purely cosmetic and the sight remained fully functional. Point of impact shift was less than 1 MOA. Unlike the other sighting devices, a second drop was performed. Results did not change, and the sight remained functional. 


My personal experience with this sight has been very promising. I haven’t dropped my rifle upside down yet, nor do I want to, but if this sight was ever under stress or hit, I would count on it every time. 

I own the Generation 1, and have yet to try the Generation 2. The only difference I could see between the two was of cosmetic difference. I got the cheaper & older model. Both gen 1 & 2 sight come with two apertures: a small one for long distances and a bigger one for closer distances. 

There was a problem with this dual-aperture set up through. When the sight was folded down into the locked position with both apertures together it does not present a problem. But when the sight flips up, the small aperture folds about 1/3 of the way down, blocking the bigger aperture. I fixed it by taking out the small aperture completely. In my honest opinion, I think that it operates better with one aperture, not having to fold the smaller one down every time you flip up the sight. 

Magpul continues to impress me with the reliability and slick design of their products. I am a big fan of Magpul and a big fan of their flip-up sights. 5/5 for performance (small aperture was an easy fix) and a 4/5 for cosmetics (scratches easy, but it doesn’t affect performance) This is a great sight for low-budget shooters who want the most for their money.

By: Michael Reyneke

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Michael is an avid shooter who reviews hunting, survival, and tactical gear for Tactical Gun Review.

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