Adam,
I shot some Wolf brand steel cased .223 polymer coated ammo in my 10" bull barrel Contender. After about 5 shots, the ejection became more and more sticky. After about 8 shots, the case stuck tight. I forced the barrel down, and bent the extractor. I final had to use my cleaning rod to get it out. Fortunately I was able to bend the extractor back into original shape without it breaking, but I sure don't want to do that again. I'm sure plenty of people have shot this without trouble, but I for one, won't be trying that again. I have had good luck with .45 Wolf ammo in my Ruger P-90, and even re-loaded it.
Safe shooting,
Lee H.