Bushmaster ORC .308 barrel nut not aligned to the gas tube

[BroncoAZ]

I got one of these rifles yesterday and wanted to add a Magpul mid length handguard.  Normall these just snap right on a 5.56 rifle and it looks like they made the heat guards a bit larger on the mid length to fit the .308.  The handguard installed fine with a little tweaking to the heat shield back near the chamber (straighten out the metal tabs so it doesn't catch on the upper part as you install).  I noticed that the handguard was crooked on the gun.  Upon further inspection I found that the barrel nut was not indexed to the gas tube, it had to be loosened a few degrees to get the handguard straight.  Unfortunately I was in a rush and got dumb.  I destroyed the gas tube when the barrel nut released, that thing was on there tight.  I read it is a standard mid length gas tube same as an AR, so I don't anticipate finding a replacement will be a big hassle.  I should've removed it before trying to budge the barrel nut.

I do have to say it seems a bit sloppy on bushmaster's part to not index the barrel nut to match the gas tube position.    The gas tube was being pushed to one side.  I didn't fire the rifle before discovering this, I'm not sure it would've made a difference.

[imschur]

Im confused.

If the barrel nut is not properly aligned the gas tube would not be able to be inserted into the upper receiver.

[BroncoAZ]

Normally the valley of the tooth on the barrel nut exactly matches the gas tube opening in the upper receiver so there is not pressure on the gas tube.  In this case the barrel nut tooth was pushing against the side of the gas tube, I had to loosen it a very little bit (2 degrees) to get it to line up and not push on the gas tube.  The rifle came from the factory with the barrel nut forcing the gas tube to the left side of the opening.

[imschur]

gotcha, I was imagining something much uglier.

And yes the barrel nuts are tight  <laughs>

So you are referring to the MOE HG correct? I found them a bear to put on my AR-15, VERY TIGHT. I have read elsewhere that guys dremel them to make them work on the 308 AR

[BroncoAZ]

It is the Moe mid length handguard.  For $35 they are worth it, I'm not in the market to add another zero to buy the Larue or DD rails for a while.  It is a tight fit, but no Dremel was required and they don't wobble at all.  I have one set on a 5.56 rifle that snap right on and fit tight. 

The barrel nut issue made the Moe handguard crooked on the gun by a couple of degrees.  Now it's straight, so a new gas tube and I'll be all set.

[ryantowry_81]

good to know it will fit. i have the exact rifle and i had no such problem with the barrel nut not indexed correctly, i have had mine together and apart a couple times since purchasing.

I am with you on not wanting to spend seriuos $$$$$ to get a free float mid length. i have been contemplating getting a stock DPMS aluminum rifle length and machining it down to mid length but maybe i will just go with the MOE for now.

could you post up some pictures?

[BroncoAZ]

Here is a picture of my rifle with some basic add ons.

[BroncoAZ]

Here is a close up of the Moe handguard and how I modified the hear shield.

[ryantowry_81]

looks good. i might just have to invest in one of those. have you got to take her out yet? how do you like the rifle?

[survivalshop]

Gives me confidence in Bushmaster Quality control.

Sounds to me like DPMS put it together, not Bushmaster.

The rifle should have been sent back as soon as it was noticed . I know, a little late now.

I would shoot them an email on what you found , ya never know ,they might surprise ya with a new gas tube .

[BroncoAZ]

I haven't had the chance to shoot it yet, unfortunately I'm getting sick and may not be able to get out this weekend.  I think the folks at LaRue might be upset with me for hanging their awesome bopid mount off of the Moe handguard. 

As for sending the rifle back, I don't think it was off enough that the rifle wouldn't function, so I doubt they would want to do anything about it.  I found out the hard way that the gas block had to be slid forward to get the new gas tube back in.  I didn't really enjoy hammering out the pins, but it's done and back together now.  The gas block was the tightest to the barrel I've ever dealt with.  I'll send them an e-mail anyway.

My pmags and Moe grip also came yesterday and are on the gun in the pic above.  Does anyone have a picture of the gap filler piece that they sell for using the Moe/Miad on the .308 rifles?  There is a small gap on the back of the grip along the curved part of the receiver.

[TacBlade]

It does not fit perfect with the filler piece Magpul makes, but I guess it makes it look a little better?

[BroncoAZ]

Thanks for the picture.  The gap on mine looks a bit smaller.

[TacBlade]

Yes, the gap is smaller.  If you look close at where the curved part stops toward the grip, the gip does not go completely flush with the receiver. That is the reason I said it does not fit the greatest.  It is still rock solid though.  Also, you can see I fixed the problem with the spring not working with the MIAD grip, as I took it out and replaced the rear takedown pin with a JP tensioning pin.  There is no wobble at all now between the upper and lower.

[98Z5V]

That Magpul filler piece is made to fill the gap in the (5.56 designed) MIAD or MOE grip and the Armalite AR-10 lower receiver.  It's not desigend to fit the gap on a DPMS-based .308 lower receiver.  The gap on the DPMS-based gun isn't as big, so that Magpul piece would have to be custom fit (meaning custom cut-up) to fill a gap on the DPMS stuff.  There's just not that much of a gap with a MIAD or MOE grip and a DPMS lower.

DISCLAIMER - I'm talking about DPMS-manufactured stuff, i.e., DPMS, Remington R-25, Bushmaster, Fulton Armory...  I can't vouch for the custom manufacturers of "DPMS-based" lowers such as Iron Ridge, CMMG, and others...  If they all share the same external dimensions on the lowers, as the original DPMS lower, then the MIAD or MOE grip will look like the one in the opening pics of this thread:

http://308ar.com/forum/index.php/topic,130.0.html