The Matech sights that come from Colt have the Picatinny marking.  I have not seen this marking on these sights from other sources.

Some time back, I’m not sure when, the U.S. Military adopted the Matech Back Up Iron Sight (BUIS) as the new rear sight for the M16A4 Modular Weapon System and the M4/M4A1 MWS. That could lead one to believe that this was the best, most durable, combat ready rear sight around. Boy would you be wrong if you thought that.

Outside the military, many people have different desires for what they want out of the BUIS. Some people want a sight that locks in place and is as solid as a bank vault, those people tend to like the Troy sights. Other people want cheap, so they go with the Magpul BUS. There are a few sights that are adjustable for range with a micrometer type adjustment such as the KAC 2-600m BUIS.  There are a wide variety of features available out there, and the Matech has a pretty unique combination of them.

The main draw to the Matech is that is had a lever on the side for changing the distance setting.  This lets you quickly set the sight for settings between 200 to 600 meters, but you can not make fine adjustment for range.

An annoyance of mine is when I can not find detailed information about a product.  I know this sight was designed for use with M855 on both the M16A4 and the M4/M4A1 Carbines but I have not been able to find out what the calibration on the adjustment is.  It might have been set for the 14.5 inch barrel, or a 16 inch barrel, or the 20 inch rifle.  It might be a blended adjustment meant to be close enough for the rifle and carbine.  We just don’t know.  But in any event, it should at least keep you on a Echo Target (40″x20″) out to 600 meters.

There is a line (with out a notch to lock it in position) between the 300 and 400m marks for zeroing a M16A4 at 25m.  When zeroing a M4 at 25m leave the sight on the 300m mark.

The sight locks down, but it does not lock in the up position.  This was chosen as to allow it to move should the rifle be dropped.  Sights that lock open can be more likely to break when locked up.  Unfortunately these sights tend to wear out and stop locking in the down position.  Countless discussion and youtube videos can be found about this.

For example:

Downsides to the Matech BUIS are:

•  It is huge, much larger than most other BUIS.
•  If you over tighten the clamping screw and bar it will break!  Snug it up and tighten 1/4 turn past that, no more than that.
•  You are suppose to replace the screw that is used to hold it on if it is removed from the weapon.  Most of us won’t have multiple screws laying around.
•  It wears out!  The rear aperture latch wears out and will not stay latched down.

Now I wouldn’t say it is a terrible sight, but I do not recommend buying one.  If you already have one I wouldn’t bother to replace it unless it breaks or wears out.  Just make sure you check the distance setting on it before you shoot.