VTAC TRX extreme slightly off center

[andy t]

I just got a new BCM lightweight midlength upper with VTAC TRX extreme.
After readjusting the small rail pieces and putting the rail back on the rifle I noticed that once I rotate the rail all the way to the right, the rails right edge is out of alignment with the upper by about a millimeter.
Is this something to be concerned about?

[Robb Jensen]

Loosen the two screws at the bottom and remove the rail from the upper and make sure the barrel nut hasn't come lose. Then reinstall the rail and line it up and tighten the two screws.

[andy t]

Robb,

Thanks for the advice. Pardon my ignorance, but can I just check the barrel nut by trying to turn it with my hand? Do I need a special wrench?
If it did come loose, would I need a special wrench to re-tighten it? What are the chances of that happening again down the road?
When I was putting the rail on, the gas tube seemed to be properly aligned.
Thanks!

[Slippers]

Perhaps the OP has some confusion about the anti-rotation tab. It doesn't have to be touching the upper receiver body. It's only there as a failsafe for the barrel nut loosening, so it can't come completely off.

[Robb Jensen]

Robb,

Thanks for the advice. Pardon my ignorance, but can I just check the barrel nut by trying to turn it with my hand? Do I need a special wrench?
If it did come loose, would I need a special wrench to re-tighten it? What are the chances of that happening again down the road?
When I was putting the rail on, the gas tube seemed to be properly aligned.
Thanks!

If it's lose it'll move by hand. More than likely the only thing is the rail isn't sitting correctly on the barrel nut. This is an easy fix.

If the barrel nut is lose:
I've seen one Troy TRX barrel nut come lose. My theory is that it was never torqued to the at least 35-40ft lbs or it wasn't torqued at least 3 times. I like them to be more than that myself, I prefer 50-80ft lbs on the Troy TRX and Troy made VTAC rails. What I do is get them to 30ft lbs after lubing up the barrel nut and receiver threads with Brownells Action Lube Plus and then loosen and retorque a little higher usually just 2-3ft lbs more each time, loosen and retorque and so on. Some times it takes a while to get it up to 50ft lbs or so. I use a DPMS barrel wrench on them. I dislike the Troy made tool that comes with the Troy versions of this rail. You do need to be very careful and take your time because it's not all that hard to bend the teeth on the barrel nut if you get a little to carried away torquing. Personally the way the teeth are on the barrel nut are my least favorite part of these rails. I'd much prefer a barrel nut something Daniel Defense has on the Lite/RIS/Omega X rails.

[Robb Jensen]

As Slippers said the anti-rotational tab does not have the touch the upper. Just align the rail and tighten the two screws. I use a little blue Loc-tite on the screws also.

[andy t]

Guys,

Thanks for the advice. I will check for a loose barrel nut. Slippers you are right. I was assuming that the indexing tab has to be against the receiver.