VTAC hand-guard and barrel not lining up?

[CENTCOM_Survivor]

So I added a VTAC hand-guard with carbine profile extension. Now that I have it all installed it seems the hand-guard and the barrel are off by 2mm at the sides. I know it doesn't sound like much but you can defiantly tell when looking at it. I replaced the upper receiver also and had to remove and reinstall the barrel. Its torqued correctly using a torque wrench and I followed all the VTAC directions to a "T". The front sight post is canted to the right but it was like that from the factory (Colt) as my rear sight post is way to the right also.

Since this is my first free float hand-guard I just want to make sure being off a little is no big deal? Thoughts?

http://i837.photobucket.com/albums/zz293/CENTCOM_Survivor/Guns/OFF1.jpg
http://i837.photobucket.com/albums/zz293/CENTCOM_Survivor/Guns/DSC07717copy.jpg
http://i837.photobucket.com/albums/zz293/CENTCOM_Survivor/Guns/DSC07622copy.jpg

[An Undocumented Worker]

I've got a Smith M&P 15 VTAC that came with the rifle length tube installed from the factory, and yes the tube is ever so slightly offcenter to one side on the horizontal plane. I've spoken with S&W about it and from what theyve seen on the uppers they had on hand that it was normal. They apparently got the uppers preassembled, by who, not sure.


Anyway, I've got buis mounted to the tube and there is sufficient leeway on the rail sections and how they mount to the top rail so as to center the buis to the barrel and minimize the amount of windage necessary to zero. Once set I used purple locktite on the rail section screws.


Overall, the JP/VTac tube has been solid and it's orientation to the barrel has remained consistent and my zero hasn't shifted.

[Skyyr]

Unacceptable. Seriously. Send it back and make them fix it.

[c0b2a]

Unacceptable. Seriously. Send it back and make them fix it.

I agree. That is something you need to have fixed.

[An Undocumented Worker]

He built the rifle from various parts, how are you gonna tell if it is the reciever, barrel, tube, or user that is the cause of the misalignment?

On mine the misalignment is barely noticeable and does not interfere with the function of the rifle.

So in this guys case, which part do you send back?

Honestly I would contact JP and see what info or solutions they have, as they are the ones who manufacture that tube.

[CENTCOM_Survivor]

Yes I did the build myself so there lies the issue.

I'm concerned it may be a upper/barrel issue and not the hand-guard. It looks like I may have to take it apart and use a lapping tool to make sure its not the upper. I would hate to have the bolt crack from being misaligned.

The upper and barrel are both Colt so I figured I wouldn't have any issues, but who knows. :confused: Is there a way to check the barrel alignment without taking it apart?

[Skyyr]

Yes I did the build myself so there lies the issue.

I'm concerned it may be a upper/barrel issue and not the hand-guard. It looks like I may have to take it apart and use a lapping tool to make sure its not the upper. I would hate to have the bolt crack from being misaligned.

The upper and barrel are both Colt so I figured I wouldn't have any issues, but who knows. :confused: Is there a way to check the barrel alignment without taking it apart?

Have you checked the distance from the handguard to the barrel WITHOUT the carbine extension? Check to see if it's still canted without it, as that would be more likely to be canted/out-of-spec than the entire upper assembly.

Also, try disassembling the upper and re-assemble it with the old upper receiver. If the old one is canted like the new one is, you have an issue with the handguard. If it's not, then it's the new upper receiver.

Either way, something is out of spec and I would not try to "fix" it myself; I'd send it in and get a replacement once I pinpointed the issue.

[Iraqgunz]

Did you remove the barrel from the upper? Since you put this together yourself I agree that it is rather difficult to go after "anyone".

I would remove the rail, and then remove the barrel from the upper. I would then check everything and reassemble it. At that point if it's still FUBAR I would see about sending back the handguard and getting a new one.


Yes I did the build myself so there lies the issue.

I'm concerned it may be a upper/barrel issue and not the hand-guard. It looks like I may have to take it apart and use a lapping tool to make sure its not the upper. I would hate to have the bolt crack from being misaligned.

The upper and barrel are both Colt so I figured I wouldn't have any issues, but who knows. :confused: Is there a way to check the barrel alignment without taking it apart?

[An Undocumented Worker]

Yes I did the build myself so there lies the issue.

I'm concerned it may be a upper/barrel issue and not the hand-guard. It looks like I may have to take it apart and use a lapping tool to make sure its not the upper. I would hate to have the bolt crack from being misaligned.

The upper and barrel are both Colt so I figured I wouldn't have any issues, but who knows. :confused: Is there a way to check the barrel alignment without taking it apart?

Call JP Enterprises they likely have answer for your question.

http://www.jprifles.com/2.1.php


It also appears that it may be possible to tweak the alignment of the tube during initial installation before the loctite cures.
http://www.jprifles.com/instructions/Rifle/JPHG.pdf


Note: While alignment of the gas tube holes between the receiver and handguard itself is not extremely critical, if you intend to use a 12:00 rail system, precise alignment of the hand guard system to the receiver becomes very important. At this time, we sug-gest using the hand guard tube with the rail attached to further refine the alignment of the outer receiver extension nut to the rail. Before the Loctite cures, slide the tube on the outer nut and install with at least two screws. Check for perfect alignment of the 12:00 rail system to the actual receiver rail and correct if necessary.

Reading that bit leaves me to believe that JP may have some tips on how to most effectively correct the allignment of the tube. But it does sound like you are going to have to reinstall it, as for getting the outer nut off of the reciever, not sure what the best method for breaking the bond on loctite 271 is, on threads that large.

[CENTCOM_Survivor]

Quick update,,, I took it to the range and it only took a few tweaks on the front sight post and it was shooting fine. My Eotech took a little more (shot way low right) but its dialed in now.
I triple checked the bolt and there is no wear or issues. Looks like it being off is just the hand guard and not the barrel/upper.
Thanks for all the suggestions/help.