That's what I was thinking.
This issue has been reported twice this week with new builds.
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Has BCM been replacing the barrels in question, or are they saying "If the gun works, we're not replacing anything."?
We'll see. Mine arrived there yesterday--waiting for a response/call or it to get shipped back. ::fingers crossed it gets fixed, not just realigned/shimmed::
The 12" C4 rails were probably just 3/16"...maybe even 1/4" closer to the barrel on the left and 1/4" further on the other side--it was definitely visible, but when I held it in place and tightened it down, I could get it to where it was barely visibly noticeable--sticking my two forefingers, one would go in a bit, the other wouldn't (so it was still off).
I have a feeling it might shoot itself out of alignment unless I used red loctite and/or a shim.
NOTE: The VTAC ALPHA 13"s were off even more...I wish I'd measured, but I'd say there was 33-40% more space between the barrel and the rail on one side.
I actually plan on running the VTAC until Fortis or someone comes out with a lightweight keymod that uses a standard barrel nut. I've now heard of 3 people with the same issue. Hopefully we'll all get it "straightened" out.
Sometimes.
I'm not being intentionally cryptic, it's just that it can be in a few different places, or with a tolerance stack that isn't visible until 10" from the barrel nut.
If it's the threads, there isn't really anything you can do.
If it's between the barrel extension and the face of the receiver, they can be "flattened"; the extent of which work can be anything between simple and soul-crushing.
The big thing to remember is that the TDP doesn't control these dimensions as tightly as needed to have precise alignment of free-floated tubes and barrels; so you can have quality components all around and still have a "misaligned" barrel and tube. Frustrating, I know, but one of the results of advancing a design that was not specifically spec'd for that setup.
This is another guy, from TOS, who just put a Troy ALPHA on his BCM blem upper...my VTAC ALPHA was off exactly like this:
http://i803.photobucket.com/albums/y...ps93ceec5d.jpg
The problem there is mounting BUIS on the rig. You may or may not be able to adjust windage enough to even get it on paper. I had the same issue with a TRX Extreme on an unnamed upper. I was able to true that setup through judicious sanding of the interface and bridging the upper & forend top rail while torquing everything down.
And yes it was a pain in the ass. :(
Yeah, for a $1200 new (non-blem) complete upper group, I shouldn't have to do all that (in my opinion--we'll see).
My hope is that they just replace it with a new one that is dead-center aligned.
My 4 year old BCM upper had the exact same problem. Regardless of the rail system/barrel nut, it was misaligned. It also had other issues, so I replaced the upper receiver, which took care of it.
When I originally purchased it from BCM, it also had a slightly canted FSB (to the left, when looking down the rifle while firing).