Interesting information - thanks, all. I've put about 500 rounds through my new Sport and I'll tell you one thing that I've found - it cleans easier, and I don't think it's my imagination. I think it has to do with the shape of the lands - the 65 degree angle of the "sides" of the rifling. It seems that any fouling just comes out easier.

On the accuracy question, I've found my Sport to be more than adequate. It performs its job as-advertised. It's not a bench rest target rifle. It's made for fun... and the M-16 it's modeled after is made for one thing, and one thing only. The Sport would perform to that accuracy criteria quite nicely, so I'm a happy camper. I can easily hit center-mass with a 1 MOA Eotech at reasonable distances. What more can one ask?