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When I bought my Colt 6920 it already had a Matech 600 rear sight installed. I attempted to remove it this afternoon and the lock screw wouldn't move and head felt like it started to strip so I stopped the attempt. My question is does this rear sight take a special tool to install and remove. The lock screw looks like a torqz screw (forgive spelling) or an allen head and neaither seems to work, I don't want to damage it. I appreciate any help.
Yeah it uses either a 1/8th hex bit or a T-15 torx bit. I would assume it was locktited in at the factory so unless you see any visible stripping of the screw head, I would just keep cranking.
If you interested in getting rid of the sight, I would be glad to take it off your hands.;)
Thanks, I'll try one of those bits.
Sometimes these companies use so much loctite it's a pain to break off. So long as there's no plastic around (def remove any optics you have on it) use a hand held torch to slowly heat the nut and break the seal.
The factory screw uses an 1/3 Allen head. It has an oversized head, but thin body, which tends to promote over torqing because the size of the Allen key used.
If you do snap the mounting screw as some of us have, we do make an improved bracket/screw retrofit kit for the Matech BUIS ;)
http://i75.photobucket.com/albums/i314/Duffypoo/RKM.jpg
The screw is rated Grade 8 plus, for reference, the gas key on the bolt carrier is rated Grade 8. The factory screw has some thread locker already applied, it's typically good for 3 to 4 screwing/unscrewing then a new drop of thread locker needs to be applied.
There goes my shot to buy it cheap.:jester:
ΜΟΛΩΝ ΛΑΒΕ
Thanks for all the replies, I did get it off with the appropriate size allen wrench.
Does anyone have a good fix for that little lock tab that holds the sight in the stowed position? Mine flips up when I drop the bolt.
I thin Harv (not sure if he's on this board, he's on TOS and lightfighters) used a drift punch and created another "tab" to friction lock it, when the original one got worn out...
Quote:
Originally Posted by 1911-A1
Take a punch and peen the detent back into form with sufficient intrusion to engage the upright. Works like a charm.Quote:
Originally Posted by Duffy
I just bought one of these for my Matech, Stout little bracket, its just what it needs...Quote:
Originally Posted by Duffy
Thanks, for $19 shipped and our backing on warranty and service, it's one of the easiest upgrade to make if you have a Matech BUIS ;)
But for as long as the factory unit works, by all means you should keep it. If the bracket breaks or the screw snaps, you know how to find us :D
Given enough removal and installation, it's not a question of if the screw will snap, but when. BTDTQuote:
Originally Posted by Duffy
The factory screw we tested to destruction snapped at 30"/LB, the screw we selected, a Grade 8 plus, broke between 45 and 52"/LB ;)
Left to us, we would have used a beefier screw still, but we can't do that without modifying the sight itself, so this is the next best thing, actually the only thing we can do given the design constraints.
I just ordered one. Thanks for making it.Quote:
Originally Posted by Duffy
:cool:
I highly recommend this part, it really is a nice upgrade, seems to make the sight sit better since the bracket doesn't tilt. Plus, BAD is a great company to buy from, they treat you right.Quote:
Originally Posted by Duffy
I broke the bracket (horizontal break end to end) on my current Matech recently and I know it wasn't over torqued. Gotta order one of these. Duffy, I was a late bloomer in acquiring a BAD ASS ST. Fantastic product.Quote:
Originally Posted by TXSlade
-Jax
Like the BAD-BSM Matech upgrade! This I have to try!
Something to keep in mind..If re/installing a Matech ibus with dried thread locker already on the screw.. make sure that you 'finger tighten' down the mounting screw as far as possible until your finger tips bleed! This will make sure that the threads are not cross threaded before applying torque with the hex wrench :D
What a surprise to see this thread resurrected ;)
Though it's only been a few years, I remember this pet project fondly. I got my Matech sight when it was still rare, I think back in 2003, and I promptly snapped the factory bolt in two.
It was my fault for not reading the manual, I was used to the heavy duty bolts on Troy, ARMS and KAC BUIS, and expected the bolt would stop turning at some point, but it kept going until it broke.
I went to the hardware store and got replacement bolts, and proceeded to snap another one before I realized the bolt wasn't going to bottom out as it would on other brands.
The oversized Allen head, and thin bolt body tend to exacerbate this, as a big Allen head necessitates the use of a large wrench, which in turn tends to make the user apply more torque he would, had the wrench been smaller, and the small diameter bolt doesn't help anyone.
We can't make the bolt thicker, but we do use a Grade 8 bolt so it's stronger, and the head is smaller than the factory one as well. While we were at it, we redesigned the bracket, though few users broke the bracket, to make it accommodate the new Grade 8 bolt, and less prone to canting on some rails.
The RKM (retrofit kit, Matech) was Battle Arms Dev's first foray into the AR/M6 market, so it carries some sentimental value for me :)
The Matech is an amazing BUIS but the bolt is crap.