I'm surprised the mod hasn't moved this one to competition and the accurate ar.  
 The Wylde chamber is named after the man who designed the reamer back in 1984.  Bill Wylde was an early pioneer in ar accuracy.  Basically a Wylde chamber is a nato chamber with a shorter and tighter throat.  It is very popular in competition where accuracy and reliability are paramount.  One hiccup from the rifle can ruin the whole match for the shooter so anything that's not absolutely reliable or doesn't work or isn't accurate gets weeded out pronto.  The Wylde chamber is still with us.