Recently, I acquired a used AR15. The drawback to my newly purchased rifle was it's lack of any type of iron sights. I began reading reviews of the various back-up sight options in order to find something with a decent track record. During this research, I came upon the Magpul Back-Up Sights. The reviews I read were mostly positive, so I decided to pick up a set of front and rear MBUS flip sights.
When I got them, I was impressed by how solid they were constructed, especially considering they are made up of about 80% injected molded plastic. Despite the very solid construction, they are also extremely lightweight.
My AR15 is a flat-top Spike's Tactical equipped with a UTG carbine-length quad rail and a rail gas block. I mounted the Magpul sights without incident, and once attached, they were very secure. Sighting them in was a bit of a challenge, however. With the rear sight windage set at dead center, and the front sight post set flush at the base, rounds were hitting approximately 2 feet off of the target at 25 yards. After about 2 full 30 round magazines and countless adjustments, I was finally able to get the rifle to hit the target I was aiming for. A little more fine tuning, and I was able to get it to hit dead-on out to 50 yards.
My observations are quite simple, really. If you are looking for a permanent iron sight for your rifle, I would suggest that you look elsewhere. If you just need a back-up for a quality optic, the MBUS will work fine, just make sure you ensure it has retained it's zero occasionally.
I will write more as I continue to use these sights. A different set of iron sights will be installed in the future, as I prefer iron sights to optics, and a comparison will be made.
Magpul BUS sights are available new from about $79 through Amazon, front and rear sights are sold separately. Better deals can be had if you do some comparison shopping online.
