Matech rear sight question

[blgjr64]

I have a Colt 6720 with the FSP cut with a 12" Centurion Arms rail. I have a Troy front folding sight and the Matech rear sight.

I have zeroed it at 50 yards and I had to push the Matech almost the whole way to the left for it to zero (see attached picture). Is this normal? Could there be something wrong? My rail and Troy front sight were put on properly (loctite etc.)

Just want to hear if anyone has seen this before.

Thanks!
15064

[gan1hck]

I believe that's within tolerances...just annoying.

Never had this with a Colt, but had it with my Bushmaster.

Also had this happen on a set of Troy BUIS because the rear Troy was canted.

[sinister]

Happens often when the front sight is on the rail and not the barrel.

No guarantee your barrel, barrel nut, rail, or your upper are aligned on a common, trued axis.

[Travis B]

Did you build the upper? Even though its fine if it drives you crazy completely disassemble the upper and redo, making sure everything is square, focusing on the barrel, nut, rail and front sight.

[AKDoug]

While mine isn't quite that bad, I have had the same issue with a factory built rifle with a floating rail and rail mounted front sight. Not much you can do but mess with the rail. In my case, I just left it and it no longer bothers me.

[halfmoonclip]

Presume the sights are mounted on the Picatinny rail. Any chance of moving the sight body somewhat to the left, so that the sight itself will be more centered? This may require adding or removing material from the mounting. A bit of shimstock might solve your problem if you must add material.
Conversely, can the front sight assembly be moved a bit to the right?
You'll have to decide if perhaps having the sight bases a bit off center (how are they positioned now? are they currently centered?) will bug you worse than having the rear sight over toward the end of its travel.
Moon

[blgjr64]

Thanks for the replies everyone.

I did not build it. It's factory built. I had Robb Jensen cut down the FSP and put the rail on for me. He did a wonderful job and Im very pleased (just like everything he has done for me in the past). I was just asking if this was a common thing with my kind of set up. I'm asking for peace of mind. If this is normal and not a major problem then I'm ok with that. I'm just making sure.

Thanks!

[Iraqgunz]

I would try a different sight to see what happens.

[Split66]

My 6920/matech is the same way, a little left and it's zero'd fine. I remember reading that there is a specific tolerance for how many clicks the windage can be off written in the milspec for the matech/M4,( 6 clicks IIRC that will pass ), so it's not really an uncommon thing to happen. Again as long as it zero's ok you are GTG. If you really want to experiment follow IG's advice.....

[blgjr64]

I would try a different sight to see what happens.

Change out the Matech? Front sight? Or both?

[Iraqgunz]

If you are sure that the rail is straight and there is nothing else going on, then I would try another rear sight to try and rule out the issue or confirm it.


Change out the Matech? Front sight? Or both?

[glock_40_caliber]

It has always been my understanding that provided you were able to zero it, drive on with what you have. I have read on here and other forums of folks using carry handles or other rear sights having to push the aperture all the way to one side to achieve zero. That being said, I have yet to see in person a sight having to be pushed all the way to one side to zero. This includes multiple issued rifles over 20 years. There has been a couple that I have seen noticeably offset to one side, with few threads on the screw left before coming in contact with the side plate.

I guess it comes down to how much do you want to dink around with it? Like someone posted above, without having the front attached to the barrel itself the combination may just not aligning perfectly. If everything is properly installed and torqued, you may end up spending more time wrenching than shooting.

[sinlessorrow]

Happens often when the front sight is on the rail and not the barrel.

No guarantee your barrel, barrel nut, rail, or your upper are aligned on a common, trued axis.

+1 a carry handle works great also to keep a rail straight when assembling it.

[Guns-up.50]

a carry handle works great also to keep a rail straight when assembling it.

Often one of the best and cheapest ways to align the rail..... This is how all my rails have been aligned

[GI_Jared]

Side question: When you did the 50 yard sight in did you have the elevation set at 350 meters (like the picture), or 200 meters?

[aguila327]

Your good. If it really gets you, do as others here have posted and try a different variety of sights. Could get expensive but maybe you can fins some friends with different types and swap out and give them a try.

[halfmoonclip]

Your good. If it really gets you, do as others here have posted and try a different variety of sights. Could get expensive but maybe you can fins some friends with different types and swap out and give them a try.

This is an excellent suggestion.
The carry handle is as well, and an A2 will give you the advantage of elevation adjustment for range compensation.
It appears you really want to use the irons; good for you!
Moon