Gas Tube Question

[TacMedic556]

I used the "search" and did not come up with what I was looking for on here. I contacted the manufacturer and have not been heard back a definitive answer yet.

The opinion of those on here, such as Iraqgunz, C4Grant etc. are highly respected and those of that caliber are who I would like to have answer my question. I am almost embarrassed to ask. As I have heard before, there is no dumb question but there are a lot of inquisitive idiots. I am an inquisitive idiot.

I was cleaning a new 14.5 inch Mid length Upper receiver today when I noticed a ever so slight "jiggle" or "wobble" to the gas tube where it protrudes INTO the upper receiver (interior). The movement seems to be side to side and maybe 1mm or so either way.

When closely examining the gas tube as I allow the BCG to slowly ride home, I can see visible movement right were the gas tube exits the front (exterior) of the receiver as the gas key on the BCG makes contact with the gas tube inside the upper receiver.

This upper came fully configured, with an "F" stamped front sight base, 14.5 inch barrel and mid-length gas system, from a reputable maker. I have not monkeyed with it at all.

I found this thread here in searching the google where it seems another individual has experienced a similar issue: http://www.thehighroad.org/archive/index.php/t-387830.html

Is the "Don't Tread On Me" guy right in his statement?

I performed the 45 degree test and it seems to pass fine.

Any clarity from the sites many experts is welcomed. Thank you for your time.

The reason I am asking, is that I have not seen this before, or noticed it on my work M4 (Colt 6933), my personal 6920, or any other AR/M4 variant I have cleaned or examined. Maybe I just never noticed it before? I checked my 6920 tonight and it was nothing like the movement on the upper in question.

[TacMedic556]

so I googled "gas tube movement AR" and came up with better results than my other searches. Looks like my question is a non issue. Here are two threads from our esteemed M4carbine brotherhood and two from ARF.....

http://www.ar15.com/archive/topic.html?b=3&f=118&t=386700
http://www.ar15.com/archive/topic.html?b=3&f=4&t=511166
https://www.m4carbine.net/showthread.php?t=69008
https://www.m4carbine.net/showthread.php?t=72614

So no problem then I take it?

[Iraqgunz]

Unless it is causing damage to the tube area where it meets the carrier key or some other issue, I wouldn't be concerned.

[Eric]

So no problem then I take it?
Right. Movement is normal. Drop the field stripped bolt carrier into the upper and observe the interface between the gas tube and gas key. As long as the gas tube slides into the gas key without resistance (light contact is normal) you're fine. Very slight adjustments can be made to the gas tube alignment by lightly bending it.

[vicious_cb]

Too much contact will increase the wear rate of your key and gas tube. You can adjust the alignment of the gas tube with the key via these instructions.

http://www.weaponevolution.com/forum/showthread.php?1613-FAQ-s-BASIC-INSPECTIONS-AND-PROCEDURES

[rob_s]

There is supposed to be movement. The gas tube, ideally, shouldn't be touching the barrel nut or the X-shaped hole in the upper. With the bolt retracted to the rear, or removed entirely, the only point of contact for the gas tube should be the FSB or gas block.