AR Sponsor
Posted: 6/19/2007 8:03:34 PM EDT
|
I shot 100 rounds of guat in my new upper last week with no problems. Today i had lots of jams where the round would extract but not eject making both the fired brass and new round get stuck inside the feed ramps The fired empty brass always on top and in line with the new round . Same ammo but the mags now have magpul ranger floor plates. I don't see how those could change anything. Another thing i was using the mag as a "bipod" since the bench at this range was so low.It was also lightly lubes as opposed to last time but don't see how that can change anything seeing how it was feeding new rounds fine? |
|
While comments are still welcome. I found this vid that i think answered my question. It was the using the mag as a "bipod" supposedly. What i described is a double feed right? great vid vids.myspace.com/index.cfm?fuseaction=vids.individual&videoID=2023734956 |
| Since it is a new upper, you may want to double check your gas key screws. If they are not staked properly, they will loosen and make your rifle short stroke. Something else to check, would be proper ejector function. If the bolt is coming back far enough to pick up the next round from the mag, it should be kicking the empty out of the ejection port. |
| gas key looks properly staked looks like the colt ones,this is a CMMG upper. Didn't realize Ar's used that much lube i lubed it not to collect gunk like you lube a glock,but if that was the problem wouldn't it not feed a new round?How do i check ejector function?.I was hoping the problem was putting pressure on the mag like i posted before anyone else think this could be the problem? |
Granted that you can't use the mag as a bipod in match shooting (prone), you can use it as a rest in free hand in rapids and a lot of shooter use this method without problems (right hand shooter). 
|
|
You can check ejector function using an empty shellcase. Hook the rim of the case under the extractor, holding the case at about a 45 degree angle from the face of the bolt. Now pivot the case with the rim under the extractor, until the case head compresses the ejector and its spring, and the case head is resting completely on the face of the bolt. You should feel resistance as the ejector is pushed down into the face of the bolt. Slowly remove the case from the bolt face. If the ejector stays put, there is a burr interferring with its proper movement, the spring is bad, or the ground slot on the side of the ejector may be dragging on the roll pin. Something else to look at since you have the bolt out, is the extractor. Make sure there is no distortion, or chunks broken out of it. Hope this helps. |
Here is the proper method to Lube an Ar15. 
|
|
Sounds like an extraction/ejection problem. Try an O-ring for your extractor. --- You can certainly underlube an AR. Those that say it should work dry are fullakrap. It is a machine, it needs lubrication. You can't overlube an AR. If you do, yes, it will be messy, but it will work fine. And it will soon blow excess lube out of the ejection port. |
AR Sponsor