AR Sponsor
Posted: 6/12/2010 8:41:24 PM EDT
|
I have an upper that has a little more than 500rnds through it and the area of the gas tube that enters the carrier key
is showing slight signs of wear/polishing on the bottom lip. Upon further inspection I noticed the gas tube moves just barely up when the key slides over it. I've tried using the eraser end of pencil to try to push the tube down but it's having no affect or it might if I pushed harder... only I just don't want to break the tube. I did push to the point that the eraser was crushed by the tube but after that point I didn’t feel comfortable pushing any harder. Should I push harder? Hell, I'm not even sure I should be messing with it because I can close the key on the gas tube without it moving by simply lifting up the back end of carrier within the tolerances of the upper receiver... What do you guys think? Any advice would be much appreciated. |
|
I purchased a well worn .mil surplus Colt Commando upper (Model 733) that had the entire bottom half of the gas tube worn flat... it was still 100% reliable. Personally, I wouldn't mess with it. Some wear is normal and usually it will wear to a point and then stop.
You can try to adjust it if you want, but if it were me, I'd wonder if I had bent it too far the other way - I mean, it's not like you'll easily spot any gas tube wear on the other side of the tube. 
An easier way to adjust the gas tube is to remove the top handguard and gently squeeze the gas tube towards the barrel. This will in effect raise the end protruding into the upper. Go slow, a little goes a long way! Worst case scenario, buy a spare gas tube for $15 and keep it in a drawer if the original ever becomes a problem. |
|
Thanks for the reply. I've already decided to leave it alone from fear of damaging the gas tube.
The Idea of adjusting the tube from the out side the receiver is one I considered but I don't at all feel like removing my overhanging Eotech 552 w/ LaRue mount along with my RISII rail; would be a PITA. |
| We do this at the factory all the time, remove the bolt from the carrier and slide it in and out slowly and feel which way the gas tube needs to be bent/aligned. You can use a screwdriver from the inside of the upper receiver, or as stated in a previous post, remove the handguards and push/bend it from the front/exterior of the upper receiver. A little rubbing is not going to hurt anything, but I do make it perfect on all my personal rifles. Take your time and bend a little at a time and you can make it perfect. The gas tube is stainless steel and will take a lot of bending without damage. Mine are all adjusted so you can't even hear the gas key going over the tube when cycled. |
AR Sponsor