Yeah, arguably the most important single gun in the history of the US. I have a paperback copy of the book he mentions at the beginning: Undaunted Courage, the story of the Lewis & Clark expedition. Excellent reading if you enjoy history.
Air guns are awesome, way more powerful than most people think. I've used .177 and .22 caliber break action air rifles to hunt small game sometimes, and I know a couple guys who have larger calibers and hunt larger critters with them. I have no doubt that a .46 cal lead roundball would go through a 1" pine board.