Short answers, pulled from the story.
Rifling refers to helical grooves cut into a rifle's barrel. The raised areas between those grooves, called lands, grip the bullet as it travels down the bore and spin it at speeds exceeding 100,000 revolutions per minute. That gyroscopic spin stabilizes the projectile in flight, dramatically improving accuracy and extending effective range compared to smoothbore weapons.
French Army Captain Claude-Etienne Minie invented the Minie ball, a conical bullet with a hollow skirt at its base. When fired, expanding gas forced the skirt into the rifling grooves, forming a tight seal without slow ramming. This allowed conical bullets to be loaded into rifles as quickly as round balls in smoothbores, and extended effective range from roughly 50 yards to roughly 300 yards.
Morgan's Riflemen, led by Daniel Morgan, used long rifles to pick off enemy cannoneers and officers during key battles. Their sharpshooting proved integral to the Battle of Saratoga and was significant at Cowpens and King's Mountain. Congress had authorized ten companies of riflemen specifically to exploit the accuracy advantage of colonial long rifles over British and Hessian smoothbores.
The record stands at 3,540 meters, set by an unnamed soldier serving with Canada's Joint Task Force 2 using a McMillan TAC-50 sniper rifle. A previous notable long-distance kill at 2,430 meters was recorded in Afghanistan during Operation Anaconda in 2002, made with a Barrett M82A1.
Post-war infantry combat analysis showed that most engagements occurred within 100 meters, making the range and power of traditional .30-caliber cartridges largely wasted. Research also found that the number of rounds a soldier fired was the strongest predictor of combat effectiveness. Smaller calibers allowed troops to carry more ammunition for the same weight and provided lower recoil and larger magazine capacity. Most modern service rifles now fire a projectile of approximately 5.56 mm.
The Grizzly was a .22-caliber rifle produced around August 2013 by a Canadian known as Matthew, using a Stratasys Dimension 1200es printer. The original version fired one shot before breaking. An improved Grizzly 2.0 fired fourteen bullets before structural strain damaged it.