Delta ring is loose, need assistance

[Bread is People]

Ok, I just received a used but still great condition LMT 16" CAR upper today and while cleaning it up, I noticed that the HGs were loose, meaning there is some rotational play (not left to right, but spinning about a 1/16th of an inch) in the delta ring assembly. It seems like the spring under the delta ring is loose, which causes the HGs to wobble a little bit.

In short, how do I go about fixing this? I've never assembled a complete upper from parts, so I am not familiar with the whole HG retaining system (meaning I pretty much only know how to remove/install the HGs). Is there a quick fix or is there more to it than I might expect?

[mvician]

normal

[bkb0000]

it's probably "normal." the delta ring does rock back and forth, with varying degrees of ease between guns. the only way your spring could be "loose" would be if the lockring that holds it in place inside the delta ring has come loose- which would be pretty obvious, as you'd see it rattling around between the receiver face and the delta ring. it should be fully within the delta ring.

[5pins]

The weld spring could be broken also. However, it sounds normal to me also.

[Bread is People]

Normal, really? There isn't anything broken, at least that I can see. Is there anything I can do to lessen the amount of play in it? Maybe tighten something?

On a related note, could this be anything to do with the barrel nut (what exactly is the barrel nut anyways)? I also just took a look at a schematic and I still don't understand how all of those parts fit onto the upper.

[Thomas M-4]

My LMT upper delta ring has some movement in it its normal.

It does not move much any more after I shoe horned in the KAC RAS LOL

[bkb0000]

Normal, really? There isn't anything broken, at least that I can see. Is there anything I can do to lessen the amount of play in it? Maybe tighten something?

On a related note, could this be anything to do with the barrel nut (what exactly is the barrel nut anyways)? I also just took a look at a schematic and I still don't understand how all of those parts fit onto the upper.

the barrel nut tightens the barrel to the receiver. the delta assembly is sort of squished between the barrel nut and the receiver, and locked in place by a lockring. the barrel nut holds it all together- pretty important part.

i seriously doubt it has anything to do with the barrel nut. its really rare, but barrel nuts can come loose. to find out, pretty much all you gotta do is pull your handguards off and grab the nut and try to twist it off as much as you can before the gas tube stops it from rotating further. the gas tube will generally hold a loose OE barrel nut in place long enough for you to notice theres a problem. if the nut moves AT ALL by hand, then it's definately loose, and you don't want to fire the weapon till it's fixed. the only way to tell for sure is to untorque it using an armorers wrench, and see how hard it is to get off.

The spiny looking thing is the barrel nut
http://c4.ac-images.myspacecdn.com/images02/68/l_01156a6345924dc29d55b6e22e434e1f.jpg

The ring immediately in front of the receiver face is the back of the barrel nut. you can see the lockring snapped into a groove in the nut, holding the spring in place inside the delta ring
http://c1.ac-images.myspacecdn.com/images02/69/l_dc393e76332a4aa6a3ca38d45620f5f0.jpg

a delta assembly, in installed order.. barrel nut, delta, spring, lockring. when installed, this assembly sits behind the splines on the barrel nut, and locked onto it by the delta ring
http://c1.ac-images.myspacecdn.com/images02/89/l_c6a2f22111ea481abb2e6aac55476d20.jpg

hope this helps

[Robb Jensen]

Lose by design.

[Ridge_Runner_5]

Good a time as any to cut it off and install a free float;)

[Bread is People]

The barrel nut is tight and everything else looks fine. I guess I'll have to get used to it. Maybe the MOE HGs will tighten it up enough when I finally get them. Anyways, thanks for the helpful input.

About the free float rail, well, if I only had the pennies to rub together...