I recently bought 500 rounds of winchester 5.56 Q3131 lot#PB91.  This ammo wont feed in my AR. My 14.5 in AR will fire the round but during the extraction the cartridge case gets stuck on the gas tube as the next round in the magazine feeds.  It is almost like the gas isnt hitting the carrier key with enough force to fully move the carrier back giving the extractor enough time to throw out the spent case.  I thought it might be the rifle so I tried a magazine full of 223 WWB from the 40rd value pack.  It fed the weaker 223 every time with no problems.

That pissed me off because why in the hell would the more powerfull 5.56 fail to feed when the
weaker 223 would.

I opened the rifle and two gas rings where together could this have been causing the problem?

Quoted: I recently bought 500 rounds of winchester 5.56 Q3131 lot#PB91.  This ammo wont feed in my AR. My 14.5 in AR will fire the round but during the extraction the cartridge case gets stuck on the gas tube as the next round in the magazine feeds.  It is almost like the gas isnt hitting the carrier key with enough force to fully move the carrier back giving the extractor enough time to throw out the spent case.  I thought it might be the rifle so I tried a magazine full of 223 WWB from the 40rd value pack.  It fed the weaker 223 every time with no problems.

If the bolt group is traveling rearward enough to grab a fresh round, then it should eject...  Curious.

I opened the rifle and two gas rings where together could this have been causing the problem?

NO!

Quoted: Quoted: I opened the rifle and two gas rings where together could this have been causing the problem? NO!

What could it be.  My rifle will feed wolf ,eagle all the shit ammo i can find it eats with glee but it wont touch gormet food who does it think it is dammit.  It does like on occasion isreali M855 ball but only when I can afford it. Could this be a tantrum of some kind?

How many rounds did this occur with.  All?  A couple?

That's very odd.

My rifle was having a short stroking problem, BUT, the only ammo that it jammed everytime was Winchester Q3131 5.56mm 55gr FMJ.  It would eject the round fine, but would jam like hell between the mag and feed ramps, or just wouldn't load another round at all.

Every other ammo shot fine, but just didn't lock the bolt back.

Weird.  My friend and I have identical carbines from the same manufacturer, purchased at the same time, his won't feed Q3131 even 2 rounds in a row (almost exactly like you describe), mine runs it fine.  Wolf, etc. works fine for him too.