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Posted: 4/14/2006 1:10:26 PM EDT
Well, against my better judgement and in an effort to save a buck, I purchased a CMT receiver for my recce build.  The build looks spectacular.  The problem is that the rail is out of spec.  My Larue ACOG mount that sits flat on my Larue rail and Colt receivers does not sit flat on the CMT receiver.  It cants to the left.  If this was a standard build, I probably wouldn't be as upset, but I'm really not in the mood to pull the barrel and Larue FF rail.  For those that think all receivers are created equal, they are not.      
Link Posted: 4/14/2006 1:20:22 PM EDT
Before this little rant did you consider talking to STAG about this? Bad apples come out, it happens but CMT makes quality in spec parts for many manufacturers out there so before you go bad mouthing them maybe you should talk to the vendor you got it from or STAG themselves and determine a mature reasonable course of action.

Steve
Link Posted: 4/14/2006 1:30:07 PM EDT
All my A3 uppers are belong to CMT.

No problems.

Who'd you buy it from? Whoever it was, i'm sure they'll make it right.

Yes, it does suck that you'll have to pull the barrel and FF HG, but that's what you get for not checking the mil-spec'ness of the receiver before mounting the barrel and FF HG.

HS1
Link Posted: 4/14/2006 1:43:28 PM EDT

Originally Posted By NUcadet07:
Before this little rant did you consider talking to STAG about this? Bad apples come out, it happens but CMT makes quality in spec parts for many manufacturers out there so before you go bad mouthing them maybe you should talk to the vendor you got it from or STAG themselves and determine a mature reasonable course of action.

Steve



Well, this is the second bad CMT receiver I've owned so I think I'll stick to my original sentiment.  I appreciate the thought, though.  
Link Posted: 4/14/2006 1:47:38 PM EDT

Originally Posted By HighStrung1:
All my A3 uppers are belong to CMT.

No problems.

Who'd you buy it from? Whoever it was, i'm sure they'll make it right.

Yes, it does suck that you'll have to pull the barrel and FF HG, but that's what you get for not checking the mil-spec'ness of the receiver before mounting the barrel and FF HG.

HS1



The build was done by someone else and truly is superb work.  Like I said, if it was a standard build I would just break it down, replace the receiver, and move on, but this upper is a work of art and I hate to have to tear it down.  The rail is perfectly aligned with the receiver and there is no contact between the carrier and gas tube at all.  It truly is an exquisite build.  Clamping type mounts appear to work fine as opposed to QD levers so I'll probably just go that route for mounting a scope.  I'll throw the ACOG on something else.
Link Posted: 4/14/2006 1:48:16 PM EDT
What was wrong with the first and what did you do about it? One of my favorite gun shops is litterally down the street form CMT and they get the CMT factory seconds, after seeing the uppers that they turn away for cosmetic blems which are for the most part indistinguishable from a regular upper I have faith in their quality control and own a number of their products.

Steve
Link Posted: 4/14/2006 1:55:05 PM EDT
[Last Edit: 4/14/2006 1:55:48 PM EDT by Bradd_D]

Originally Posted By NUcadet07:
What was wrong with the first and what did you do about it? One of my favorite gun shops is litterally down the street form CMT and they get the CMT factory seconds, after seeing the uppers that they turn away for cosmetic blems which are for the most part indistinguishable from a regular upper I have faith in their quality control and own a number of their products.

Steve



My first upper must have been a second as the T-numbers ran crooked up the rail slots.  Purely cosmetic, but bad machining is bad machining and I certainly didn't pay a seconds price.  I'm not real thrilled with companies that release seconds as the parts aren't marked in any way and tend to get into the mainstream eventually being sold as firsts.  Bad finish is one thing, but for a CNC machined rail to be out of spec means tolerances aren't being checked somewhere.  Consistency is what makes a company top tier.
Link Posted: 4/14/2006 3:18:42 PM EDT
[Last Edit: 4/14/2006 3:19:13 PM EDT by Teknic]
Link Posted: 4/14/2006 3:28:41 PM EDT

Originally Posted By Teknic:
I've sold hundreds of STAG receivers.  I haven't had one return due to quality.  It's really too bad you were so unlucky with your builds.  

PS.  Why not ask your dealer to help you out?



I've contacted the dealer that built the upper.  I just needed to vent a little.  
Link Posted: 4/14/2006 3:38:47 PM EDT
Link Posted: 4/14/2006 3:53:11 PM EDT
You know what you should have done, don't you?

Link Posted: 4/14/2006 3:53:56 PM EDT

Originally Posted By ar-wrench:
You know what you should have done, don't you?




Yes.  
Link Posted: 4/14/2006 4:25:12 PM EDT
[Last Edit: 4/14/2006 4:26:02 PM EDT by LeitnerWise]
Link Posted: 4/14/2006 4:35:23 PM EDT

Originally Posted By LeitnerWise:
Bradd_D:  I'm having trouble visualizing the problem with your rail; is there anyway you could describe it in more detail?  What Larue mount are you using?  

Regarding the first problem you had with CMT/Stag; they send out receivers for laser marking and with the number they move on a monthly basis, I wouldn't be surprised if one or two are off - you wouldn't believe the problems we've had with laser engraving - even getting them to mark an entire batch in the same typeface was a chore!  (we now do this ourselves).  Anyway, knowing the guys in New Britain as I do, they would have swapped that out directly if asked.  

Any info you can give would be helpful!



No prob...thanks for the insight.  I tried Larue ACOG and Aimpoint mounts (the new style with locking lever).  Regardless of tension, when you close the lever the mount and scope assembly cants to the left.  When I attach a mount that is held by a clamp (i.e. a PRI Aimpoint mount) it sits flat.  I also noticed that the levers required an unusual amount of tension adjustment before they would clamp securely on the rail.  As an aside, my Troy rear sight (with the new style clamp) came very close to not tightening down on the rail.  
Link Posted: 4/14/2006 4:41:19 PM EDT

Originally Posted By Bradd_D:

Originally Posted By LeitnerWise:
Bradd_D:  I'm having trouble visualizing the problem with your rail; is there anyway you could describe it in more detail?  What Larue mount are you using?  

Regarding the first problem you had with CMT/Stag; they send out receivers for laser marking and with the number they move on a monthly basis, I wouldn't be surprised if one or two are off - you wouldn't believe the problems we've had with laser engraving - even getting them to mark an entire batch in the same typeface was a chore!  (we now do this ourselves).  Anyway, knowing the guys in New Britain as I do, they would have swapped that out directly if asked.  

Any info you can give would be helpful!



No prob...thanks for the insight.  I tried Larue ACOG and Aimpoint mounts (the new style with locking lever).  Regardless of tension, when you close the lever the mount and scope assembly cants to the left.  When I attach a mount that is held by a clamp (i.e. a PRI Aimpoint mount) it sits flat.  I also noticed that the levers required an unusual amount of tension adjustment before they would clamp securely on the rail.  As an aside, my Troy rear sight (with the new style clamp) came very close to not tightening down on the rail.  



So you think it's a width issue?  Care to put calipers to the rail width on the CMT?

Link Posted: 4/14/2006 4:46:18 PM EDT
[Last Edit: 4/14/2006 4:47:54 PM EDT by fla556guy]

Originally Posted By Bradd_D:

Originally Posted By LeitnerWise:
Bradd_D:  I'm having trouble visualizing the problem with your rail; is there anyway you could describe it in more detail?  What Larue mount are you using?  

Regarding the first problem you had with CMT/Stag; they send out receivers for laser marking and with the number they move on a monthly basis, I wouldn't be surprised if one or two are off - you wouldn't believe the problems we've had with laser engraving - even getting them to mark an entire batch in the same typeface was a chore!  (we now do this ourselves).  Anyway, knowing the guys in New Britain as I do, they would have swapped that out directly if asked.  

Any info you can give would be helpful!



No prob...thanks for the insight.  I tried Larue ACOG and Aimpoint mounts (the new style with locking lever).  Regardless of tension, when you close the lever the mount and scope assembly cants to the left.  When I attach a mount that is held by a clamp (i.e. a PRI Aimpoint mount) it sits flat.  I also noticed that the levers required an unusual amount of tension adjustment before they would clamp securely on the rail.  As an aside, my Troy rear sight (with the new style clamp) came very close to not tightening down on the rail.  



Maybe it's not the CMT.....maybe it's the mount.  If your pri sits flat, and your larue doesn't...maybe it's the larue mount and not the upper?

Link Posted: 4/14/2006 4:46:22 PM EDT

Originally Posted By DrMark:

Originally Posted By Bradd_D:

Originally Posted By LeitnerWise:
Bradd_D:  I'm having trouble visualizing the problem with your rail; is there anyway you could describe it in more detail?  What Larue mount are you using?  

Regarding the first problem you had with CMT/Stag; they send out receivers for laser marking and with the number they move on a monthly basis, I wouldn't be surprised if one or two are off - you wouldn't believe the problems we've had with laser engraving - even getting them to mark an entire batch in the same typeface was a chore!  (we now do this ourselves).  Anyway, knowing the guys in New Britain as I do, they would have swapped that out directly if asked.  

Any info you can give would be helpful!



No prob...thanks for the insight.  I tried Larue ACOG and Aimpoint mounts (the new style with locking lever).  Regardless of tension, when you close the lever the mount and scope assembly cants to the left.  When I attach a mount that is held by a clamp (i.e. a PRI Aimpoint mount) it sits flat.  I also noticed that the levers required an unusual amount of tension adjustment before they would clamp securely on the rail.  As an aside, my Troy rear sight (with the new style clamp) came very close to not tightening down on the rail.  



So you think it's a width issue?  Care to put calipers to the rail width on the CMT?




As much as a man hates to admit it, I don't own a set of calipers.
Link Posted: 4/14/2006 4:47:14 PM EDT

Originally Posted By fla556guy:

Originally Posted By Bradd_D:

Originally Posted By LeitnerWise:
Bradd_D:  I'm having trouble visualizing the problem with your rail; is there anyway you could describe it in more detail?  What Larue mount are you using?  

Regarding the first problem you had with CMT/Stag; they send out receivers for laser marking and with the number they move on a monthly basis, I wouldn't be surprised if one or two are off - you wouldn't believe the problems we've had with laser engraving - even getting them to mark an entire batch in the same typeface was a chore!  (we now do this ourselves).  Anyway, knowing the guys in New Britain as I do, they would have swapped that out directly if asked.  

Any info you can give would be helpful!



No prob...thanks for the insight.  I tried Larue ACOG and Aimpoint mounts (the new style with locking lever).  Regardless of tension, when you close the lever the mount and scope assembly cants to the left.  When I attach a mount that is held by a clamp (i.e. a PRI Aimpoint mount) it sits flat.  I also noticed that the levers required an unusual amount of tension adjustment before they would clamp securely on the rail.  As an aside, my Troy rear sight (with the new style clamp) came very close to not tightening down on the rail.  



Maybe it's not the CMT.....maybe it's the mount.  If your pri sits flat, and your larue doesn't...maybe it's the larue mount and not the upper?




It's two Larue mounts that sit flat on every other rail I have (Colt, Larue, and KAC).
Link Posted: 4/14/2006 4:48:35 PM EDT
ok, just a thought.  Calipers are pretty cheap at home depot.......
Link Posted: 4/14/2006 5:07:49 PM EDT
Link Posted: 4/14/2006 5:13:47 PM EDT

Originally Posted By LeitnerWise:
If there's anything we can do let me know?



How about installing a piston on my Colt upper?  
Link Posted: 4/14/2006 5:14:54 PM EDT

Originally Posted By LeitnerWise:
Bradd_D:  I've got an idea now; can't remember off the top of my head what CMT use as a datum on their uppers - we used the rail after broaching - it's not unusual for receivers to "walk" after or during machining and it sounds from your description that this is the case.  I can tell you for sure the CMT/Stag have excellent QA on their forgings and batch raw receivers by tolerance prior to initial machining.  Problems do occur, I'm sure that they would swap it out no questions asked.  

If there's anything we can do let me know?



If you would stick with DPMS you wouldn't have this problem.
Link Posted: 4/14/2006 5:29:04 PM EDT
Link Posted: 4/14/2006 5:50:40 PM EDT
Link Posted: 4/14/2006 6:03:23 PM EDT
[Last Edit: 4/14/2006 6:04:03 PM EDT by HighStrung1]

Originally Posted By terrydavis:

Originally Posted By LeitnerWise:
Bradd_D:  I've got an idea now; can't remember off the top of my head what CMT use as a datum on their uppers - we used the rail after broaching - it's not unusual for receivers to "walk" after or during machining and it sounds from your description that this is the case.  I can tell you for sure the CMT/Stag have excellent QA on their forgings and batch raw receivers by tolerance prior to initial machining.  Problems do occur, I'm sure that they would swap it out no questions asked.  

If there's anything we can do let me know?



If you would stick with DPMS you wouldn't have this problem.



Ever seen a DPMS Upper Receiver with the splintered "A" forge marking before?

HS1
Link Posted: 4/15/2006 3:36:54 AM EDT

Originally Posted By Bradd_D:

Originally Posted By NUcadet07:
Before this little rant did you consider talking to STAG about this? Bad apples come out, it happens but CMT makes quality in spec parts for many manufacturers out there so before you go bad mouthing them maybe you should talk to the vendor you got it from or STAG themselves and determine a mature reasonable course of action.

Steve



Well, this is the second bad CMT receiver I've owned so I think I'll stick to my original sentiment.  I appreciate the thought, though.  



Sorry, but the longer CMT is in the AR business, the more their errors seem to multiply. I own three CMT built lowers (2 Rock Rivers and one Century) and and two of their flat top uppers (1 Rock River and 1 Stag) and every one of them has some sort of defect.

The last two pieces of theirs I got, an upper, and a stock tube, had finish defects, and I had to file the notch that allows the port cover to close by hand, because they forgot to do it. The stock tube finish comes off on the rag every time I wipe it down, and the shiny black anodising is already starting to show thru.

Same old atory.  Company starts out making good stuff the right way. Gets popular, and then starts cutting quality control problems because cranking out quantity becomes more important than crossing the Ts and dotting the Is

Yeah, I'll probably keep on getting the odd Conti piece, and putting up w/the defects, but I doubt I'll mail order anything else.  If I can inspect it before purchase maybe I can avoid some of the crap.


And yes; they beat DPMS by 5 miles.
Link Posted: 4/15/2006 4:54:01 AM EDT

Originally Posted By shamayim:

Originally Posted By Bradd_D:

Originally Posted By NUcadet07:
Before this little rant did you consider talking to STAG about this? Bad apples come out, it happens but CMT makes quality in spec parts for many manufacturers out there so before you go bad mouthing them maybe you should talk to the vendor you got it from or STAG themselves and determine a mature reasonable course of action.

Steve



Well, this is the second bad CMT receiver I've owned so I think I'll stick to my original sentiment.  I appreciate the thought, though.  



Sorry, but the longer CMT is in the AR business, the more their errors seem to multiply. I own three CMT built lowers (2 Rock Rivers and one Century) and and two of their flat top uppers (1 Rock River and 1 Stag) and every one of them has some sort of defect.

The last two pieces of theirs I got, an upper, and a stock tube, had finish defects, and I had to file the notch that allows the port cover to close by hand, because they forgot to do it. The stock tube finish comes off on the rag every time I wipe it down, and the shiny black anodising is already starting to show thru.

Same old atory.  Company starts out making good stuff the right way. Gets popular, and then starts cutting quality control problems because cranking out quantity becomes more important than crossing the Ts and dotting the Is

Yeah, I'll probably keep on getting the odd Conti piece, and putting up w/the defects, but I doubt I'll mail order anything else.  If I can inspect it before purchase maybe I can avoid some of the crap.


And yes; they beat DPMS by 5 miles.




Ditto
Link Posted: 4/15/2006 9:56:15 AM EDT
I think alot of this has to do with them manufacturing for S&W's new line of AR's. It seems most of these problems have surfaced recently since they started making the S&W line. Perhaps they are so focused on that contract they are letting their own QC go by the wayside? Wouldn't be the first time this has happened with a company.

Steve
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