I'm watching a show on NetGeo about tank technology. Older tanks as we know had smaller bore cannons. So, like modern firearms, they had rifling to stabilize the round. With bigger rounds, like what the Abrams fires (125mm). There is no need for rifling, as it's not as accurate. When a round leaves the barrel of an Abrams tank, it's traveling over 3,000 mph. The rounds stabilize themselves. I know, as we all do, no modern small bore weapon can send a projectile at over 3,000 mph. Imagine though, if there was a way to increase projectile speed, and have no need for rifling. I know that it's way out there. Imagine though, if there where rounds with self containing fins, that would stabilize the round. Like the sabot anti tank round. Imagine a sniper, being able to accurately hit a man center mass at at 2,000-3,000 yards, with a large bore rifle. Who knows where technology will take the next generation of firearms.