I am going crazy with this AR, and I need your help.  Heres my situation:

    I have a home built midlength carbine (Superior lower on a Del-Ton kit) with a 5.56 barrel.  It has approx. 400 rounds through it.  I just got it back from the gunsmith where he did some fine tuning on the bolt lugs.  Prior to this I was having some problems extracting cases, and he determined that the bolt lugs were the culprit.  I took it to the range today to function test it.  
    I go through 60 rounds of Remington 55 gr. without one problem.  Everything is good until I decide to fire some wolf, as I am figuring if it will eat wolf it will eat anything.  I fire one round of polymer wolf and the case gets stuck in the chamber, and the extractor rips the case rim off.  The case is stuck so tight I can't remove it at the range and I have to tap it out at home with a cleaning rod and hammer.  I checked the case and it doesn't appear to be blown out or damaged (except for the torn off rim).

Why does my rifle shoot brass fine, but will not extract wolf.  I don't plan on shooting wolf on a regular basis, however I am of the mind that if it won't feed anything I throw at it, I can't call it completely reliable.  Does this sound like an ammo problem or a rifle problem?  Has anyone else seen something similar happen?  Any help would be much appreciated.


Thanks,
Pedro

Contrary to what others might try to tell you, THERE IS NOTHING WRONG WITH YOUR GUN ! Wolf is a crap shoot, and this kind of stuck case jam is a very common occurrence, particularly if the barrel is heated up or dirty. Do not futz with your gun to try to "fix" a non-existant problem. Just shoot brass ammo.

If you must shoot Wolf, use a chrome-lined 5.56 chamber, keep a chamber brush handy and clean out the chamber after each string, and don't get the barrel too hot. If a Wolf-reliable AR15 is a must-have for you, then you will justhave to keep buying new barrels from random vendors until you stumble on one that runs acceptably .

Quoted: Barrel may just have some chamber rings (reamer cuts) that have not been smoothed out yet. Get another 500 to 600 more rounds of good ammo through it, then try the Wolf again.

this sounds like the problem. I would not mess with the bolt lugs anymore. you may also want to get yourself a Wolff xtra power extractor spring to help.

you should also shoot more "good" ammo to break it in more and smooth things out and don't forget to clean that chamber after you shoot it.

Like others have said, it just depends on the rifle.
I have a M&P15T that will go 200-220 rounds before getting stuck case failures.  Run a chamber brush and some Breakfree and its back in action for another 200.  Using brass case ammo this rifle has gone up to 500 rnds without a problem.
My Bushy, on the other hand, will run Wolf all day long.  Its gone through 720rnds in one sitting without a hitch.  
Test, and get to know the limits and capabilities of each rifle.