Matech sight lock detent problems [Archive]

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1911-A1

01-20-11, 15:38

I have a Matech rear BUIS that I got a while ago. I really like the design, the profile of the sight stalk, and the adjustments.

What I don't like is the tiny bump that is supposed to hold the sight in the closed position until you need it. It's just a little metal nub, that's it. It doesn't work at all. Even dropping the bolt will cause it to pop open.

Is there a fix for this? Has anyone come up with a good solution?

http://3.bp.blogspot.com/_59GYpEVAu0U/TNO0gclQXJI/AAAAAAAAAho/CkVNAVOR29Q/s1600/matech-buis.jpg

sapper36

01-20-11, 16:03

Not to sound rude but getting better sights will probably be your best bet. I ran the Matechs on two of my rifles and finally gave up on them. I ended up going with chopped carry handles and couldnt be happier. If you did want or need to stay with a folding sight there are a bunch of companies that have much better locking devices than the friction bump you mentioned.

1911-A1

01-20-11, 16:45

Bubba FAL

01-20-11, 21:18

Not intimate with the design of the Matech, but: Is there a spring return on the lock button? Can you get the thing apart enough to access said spring? If so, take some measurements (spring length when relaxed, coil and wire diameter) then see if you can find a similar spring to replace it with from an industrial supply warehouse such as McMaster-Carr. The replacement should have the same relaxed length and coil diameter with a slightly thicker wire diameter. The stronger spring will increase the effort needed to release the sight post, but should keep the post locked down during recoil.

FWIW - It'll likely cost you more for shipping than it will for the new spring (and you may have to buy the spring in a bulk quantity).

All depends on how much effort you want to expend to keep your Matech.

Blowby

01-20-11, 22:55

Spring pressure is forcing it open. The little nub holds it in the down position.

I've been using one for about 2 1/2 years and haven't had any problems. I use it for back up sight training and to co-witness with my M2 comp which will help on range targets since it trims the light and makes the dot round for these older eyes. I always lube it and keep from excessive deployment.

gbackus

01-20-11, 23:09

I had a similar issue, on both of mine the pin was actually walking out under recoil, these came on new colt rifles so I assume they were genuine matech sights.

I'm wondering if they were possibly a bad batch, but didn't feel like going through the hassle of getting them replaced, so I just bought some Troys.

Kilo 1-1

01-20-11, 23:24

I saw it for $30 at a gun show, new in wrapper, so I grabbed it. I have a DD fixed BUIS on my main rifle. I got this partly to finish the A4 clone I was building.

I just wanted to know if there was something I could do to make it better.

There have been reported issues of this with troops using these sights (heavy use, harsher conditions)....but since you got them for $30 at a gunshow, it is possible you got an airsoft copy? I've seen airsoft knock offs of the matech come out of China in the past.

I've had mine more than 2.5 years...granted they're not the best design, it hasn't crapped out yet.

Pappabear

01-21-11, 00:39

I would second the airsoft warning. I almost fell for some airsoft shit.
I have those sights on a 6940 and they have never popped up, nor do they feel like they will.

Quib

01-21-11, 05:51

I had a similar issue, on both of mine the pin was actually walking out under recoil...

I had the same issue.

1911-A1

01-21-11, 08:11

I wondered myself if it was a knockoff. I've looked it over pretty carefully, and it seems identical to real Matechs. Same weight, construction, components. I'll post pics tonight or this weekend, and maybe you guys can tell me for sure.

Redhat

01-21-11, 08:31

Sometimes the pin walks out and you can push it back in to fix the problem. Otherwise I would just replace it.

zacbol

01-21-11, 08:48

I have the MaTech on my 6940 and don't have any problems or find it particularly less usable than the KAC Micro on my SR15. But then I probably don't know enough to see it's deficiences.

Ignoring issues with the detent (whcih I've not had), what is it in particular that people dislike about it?

EDIT: Ah, nevermind, found this with some complaints: https://www.m4carbine.net/showthread.php?t=10875
I personally still like it fine and none of the things here have been issues for me.

ST911

01-21-11, 11:14

The nub that retains the upright in the down position is prone to friction wear. When it no longer keeps the rear down, take a hammer and punch and gently peen it to restore function.

LONGBOWAH

01-22-11, 09:21

There's a couple hundred thousand of 'em running around between Afghanistan and Iraq...they seem to be holding up well...and soldiers are notoriously hard on gear.

While the range adjusting knob gets moved/changed all of the time, none of mine have ever self-deployed.

cjt50

01-22-11, 16:16

Redhat

01-22-11, 18:25

The nub that retains the upright in the down position is prone to friction wear. When it no longer keeps the rear down, take a hammer and punch and gently peen it to restore function.

Skintop911,

Could you post a picture of that?

J_ROC7

01-23-11, 03:16

I been in the army alittle while and I have alittle experience with this BUIS, its hard to explain but it has a detent in there that sometimes works it way lose, you can use the tip of a knife to tap it back into place.

Frens

01-23-11, 03:25

What I don't like is the tiny bump that is supposed to hold the sight in the closed position until you need it. It's just a little metal nub, that's it. It doesn't work at all. Even dropping the bolt will cause it to pop open.

Is there a fix for this? Has anyone come up with a good solution?

seems to be a common issue with the Matech...I've heard that stacking that tiny bump should fix the problem

I used to own a Matech and I liked it. Got mine used and survived a 17months tour in Astan without problems.