Gas tube contact on barrel nut

[JediGuy]

Here are some pictures of the original problem. If someone sees something obviously out of spec, I’d love to hear.

I messed around with a tube bender and found I do not (yet) have a light touch. “lol”

But it is better than how it started. Still some contact, but improved. I had to finish this so I can use it in an upcoming class, but I may purchase a BCM or Trajectory Arms gas tube after the class to see if there is a better fit without adjustments to the tube. As good as Core barrels are supposed to be, I would prefer “perfection” on this upper.

[georgeib]

I don't see a problem in these pics. If you're able to slide the BCG in without issue, it's GTG.

[ViniVidivici]

Right on dude, I see a can of Aeroshell on the bench.

I agree with George, to me that looks fine. As long as everything's kosher with the carrier and how it's contacting the tube, I'd just leave it.

It seems the design of this particular barrel nut is such that this amount of contact is inevitable.

[556Cliff]

I can't see anything wrong either, other than the gas tube touching the barrel nut. I don't have any experience with that handguard so I can't say if it's a fluke or if it's that way with all the barrel nuts for that particular handguard.

[DwayneZ]

It's a fully functional rifle? So the question is what?

[JediGuy]

It's a fully functional rifle? So the question is what?

It’s a new upper.

My goal recently has been to maximize the accuracy potential, including minimizing any unnecessary contact points with the barrel.

[DwayneZ]

It’s a new upper.

My goal recently has been to maximize the accuracy potential, including minimizing any unnecessary contact points with the barrel.

Perhaps that contact is helping to stablize the tube? I not sure the contact is causing any accuracy issue from your setup.

If the barrel nut is where it needs to be, index the nut to upper, also place a mark on the nut edge directly under the tube, take nut off and run a 3/16" or 5/32" round nose carbide down the nut, thus making a shallow groove to provide the no-touch you are looking for. Some type of setup on a mill is needed though. Re-install nut back to index. I assume you only need like maybe 10-20thou depth for the needed clearance? You can flat mill it, but that's taking off more than you need to.

If you want the clearance, not many options, etc. Do they make a smaller OD tube?