Need some help from the AR people.

[BobOfTheFuture]

Hello folks.

Almost a year ago I bought a BCM upper assy. a 16 in. mid gas system with a Troy TRX free float rail. It arrived built by them.

Since then I have been troubleshooting. The upper shoots hard left and so low it was off the paper, beyond the elevation adjustment on the gun. It took twenty or so clicks right and I had to cut down my front sight post to get it to zero.

As I have discovered with a bubble level the flattop upper and the TRX rail are not square. The rail 'points up' and to one side as it gets farther away from the reciever. I returned the upper to BCM with a good description and markings showing the evidence of the issue on the upper. They sent it back with a good sheen of oil and took the shims out from behind my comp and put a crush ring back in. The problems, as described, remain un changed. No invoice or such saying what they did.

What do I do? Cut my losses on this waste of cash or continue to badger BCM to make good on a borked upper? Ive gone though some other issues with this upper (I bought at the same time two Troy flip sights, and they sent me one of the ones with the malformed mounting brackets)

I've about had it...

 

[autospike]

I may be out of touch, but this is the first negative thing I've heard about BCM.

I would *CALL* them and talk to someone. Ask them what they did and why. Tell them it's still giving you trouble and need a resolution. Make sure to tell them what your expectations are. Be polite but firm.

 

[highorder]

I would *CALL* them and talk to someone. Ask them what they did and why. Tell them it's still giving you trouble and need a resolution. Make sure to tell them what your expectations are. Be polite but firm.

This.

BCM should take care of you.

 

[BobOfTheFuture]

I emailed back and forth with one of their reps and did exactly what they said. RMA numbers, Detailed description, Hell, I even found the problem and marked it on the upper in pencil. Instead they pulled the comp and replaced the shims that come with the comp with a stock crush washer.

Should I really have to fight, and pay to send this upper back twice for such an expensive piece?

This is the first negative Ive heard about Bravo too, Thats why I spent more for their stuff. Please don't take this as a hit piece, had they fixed the issue then all I would have to say is how courteous and fast the repair service was.

 

[JustinJ]

What type of sights? How steep is the upward slant of the Troy TRX and how long is it?

 

[boricua9mm]

*Nevermind, I seem to have misinterpreted the OP*

 

[Zerodefect]

Sounds like they disassembled and reassembled to check for barrel/reciever fit. They missed the fact that you're useing a sight on your rail system somehow.

I'd send it back again, or diassemble the deffective Troy rail and exchange the rail with Troy.

 

[SwissArmyDad]

I'm in agreement with others here. I think CALLING them is the next step, as SO much can be lost via email. Be courteous but firm.

I think their high level of quality and assumingly high attention to detail should be enough to make things right on your end.

Also, have you taken the assembled gun to the range and do some testing with a laser boresight or something of the sort? swapped rails out temporarily for a different setup?

Maybe ask the range officers or a member to borrow a set of BUIS or a spare optic, for a few moments to preclude the possibility of faulty sights?

 

[d2wing]

+1 on Zerodefect

 

[BobOfTheFuture]

Justin, the sights dont matter, And I dont have the tools to measure the angle, only the level to prove the 2 parts are on a different attitude.

Swiss- I put a proven set of sights from another gun on this one with the same issue. This is before I found the rail out of alignment.

Zero, the email answered their questions in a very curt manner. For them to have missed it they either ignored it, or assumed I didnt know what I was talking about. This is fair enough, but at least check it yourself, any moron can run a bubble level...

Has anyone dealt with these clamp on rails enough to know If I can loosen and try to get it more square? Or would that be a waste of time.

By the way, Ive used a few straight edges, I dont belive the rail itself is warped through its length, Just not mounted correctly or the nut isnt square.

 

[JustinJ]

If the sights are crooked they certainly do matter. Not to mention there are two different types of rail mounted front sights of differing heights.

If the angle difference between the rail and receiver is too slight to discern with the naked eye i would check to verify whatever sight being used is not the issue.

I have a 9" Troy TRX rail on one of my ARs with a quality flip up front sight attached The Troy TRX has an indexing notch to align it's top rail with that of the receiver. The rail is held in place by two allen screws that tighten it around the barrel note so those should obviously be checked.

 

[SwissArmyDad]

Understood, Bob, I figured you might have...thought I'd mention it, though.

Here's some other spitballin' idea's:

1. Could a machining defect cause the rail to afford a strong perch for the sights, that are nonetheless not aligned with the bore? something where the front of the rail ends up higher than the rear? (Rather than a misalignment as they seemed to think was the cause? If so, a quality machinist might be able to remove the asymmetry for you.)

2. Have poor quality of lands and grooves, and or a damaged muzzle crown been ruled out? Also would Poor/incomplete/grossly asymetrical machining of the muzzle brake (if fitted) be possible?

And one question, is the point of impact consistant? or does it vary wildly? E.G. do you get .5-1" groups in the same spot hard left and low?

 

[BobOfTheFuture]

Justin, once again the problem was identical with 2 different sets of sights. The sights on the gun are troy SPLP bought as a set. I have verified they are the same height. The old problem with the sights was the rear was canted due to a bad bracket, which apperently was a known Troy issue. This was solved.
Whats funny is that canting was causing the poi to be closer to the proper zero, due to the rail.

Swiss, The comp was added after I noticed the issue, and caused no change. The crown and lands and grooves are all as new. This rifle does also still has less then 500 rds through it.

A machining defect Is what I think the problem is, somewhere in the meeting point of the rail and the barrel nut, or the barrel nut itself. I have yet to loosen the rail, thinking that not doing that was best for the warranty.
I dont think I should have to pay a machinist to work on a brand new top grade upper, no?

This rifle has not shot as good a group as I wish it would. I was going to worry about this after this issue was solved, if it still existed. That said, with the fresh sheen of oil on the upper from BCM, when I grab the barrel and the rail and try to flex them, oil seeps from between where the top rail and flattop touch. This suggests movement.

 

[BobOfTheFuture]

I would just like to add, thanks for the replies. Sorry if I seem short with some of my answers, I am just pissed about the rifle. You guys are helping me think objectively, and I appreciate it.

 

[taliv]

definitely a bummer. i had one part that was bad from BCM before and got it exchanged without too much hassle. everybody makes mistakes now and then. keep after them, as others have said.

 

[Welding Rod]

I had some bad gas rings from BCM. I returned them by US Mail asking for a replacement and they claimed they never recieved them. So I was stuck. Not saying it couldn't have been the USPS, but in any case I would expect most gun manufacturers today to simply eat the small lose either way and just send out a new set. Honestly I was surprised they didn't.

 

[Al Thompson]

Emails and calls are sort of ~impersonal.

At this stage, I'd actually send them a letter addressed to the company president outlining the issue. Mention that you purchased based on companies stellar performance, etc., etc.

 

[BobOfTheFuture]

Well, when I went to BCM; Their support says to send an email. I did, and followed all instructions I recieved.

 

[SwissArmyDad]

I would just like to add, thanks for the replies. Sorry if I seem short with some of my answers, I am just pissed about the rifle. You guys are helping me think objectively, and I appreciate it.

Nah, didn't get that sense at all. Always good for me, too, to get a fresh set of eyes on a problem.

Oh, and Al, I hear what you're saying about calls and emails, but I think to most people a phone call is definitely the best way to communicate. Snail mail is unreliable and slow these days, in my experience, and so much can be lost via email.

As someone who troubleshoots complex, technical issues on a daily basis, I can tell you verbal communication, in person if possible, (over the phone being a close second) has definitely resolved some major miscommunications and issues for me over the years.

 

[madcratebuilder]

The centerline of the floating tube not matching the centerline of the barrel is not that uncommon. Could be the barrel nut not machined correctly or even the tube.

I saw one tube that canted a eighth inch off center, not good for a $250 tube. BCM like any company can have a problem child.

 

[BobOfTheFuture]

I loosened the rail. I am still fiddling with it, but it looks like it requires a gap at the top, between the flattop and the top of the rail.

I googled "troy trx install how to" and got a arfcom thread about someone who put it on and pushed it against the reciever and got the same arc. They blamed it on installer error and said a gap is nessasary.

We'll see...

 

[BobOfTheFuture]

Well, that gap is needed. I patiently set it perfectly, got it perfectly centered. Tightened the screws per Troy's intructions. 'bonked' it with my hand to simulate normal use and it settled right back into its bowed situation. So It looks like this rail requires the use of shims, or it or the barrel nut are faulty.

 

[SwissArmyDad]

interesting.

Lets say you could get your $$ back for that faulty handguard/rail tube.

Could you replace it with a Low-pro gas block clamp-on A2 or folding front sight and magpul MOE handguard with rails? Does that BCM upper have a low-pro gas block that rides under the Troy tube?

 

[W.E.G.]

Should have bought a Colt 6940 if you want properly-aligned frontage rail estate.
The completely-ONE-PIECE upper receiver starts at the buffer tube and ends at the gas block.
Light as a feather too.



Did you REALLY think the completely-separate-part rails on the aftermarket front handguards were going to be square with the completely-separate-partupper receiver rail?

 

[2WheelsGood]

Not to mention there are two different types of rail mounted front sights of differing heights.

That's what I was thinking. If you have a front sight designed for a railed gas block but mounted on a free-float rail, it would definitely be too high (shooting low).