[Catfish]

I`m not sure about the twist, but it might be based on the fact the the air around a high presure area move in a clock wise direction in the Northen hemispher and counter clock wise direction in the Southern, low presure areas are the oppsite. The little funnel in your bathtube will move clock wise in the Northen hamisper and counter clcok wise in the Southern. As for the gain twist it started long ago because it was easier to keep the bullet from slipping in the rifleing if it were started at a slower rate then increased after you had it spinning than to shuve it into a very fast twist befor itstarted to spin.