Re: The Answer
Frederick Nelson
For Ken's benefit, the word "Jaeger" means "hunter."
The usual Jaeger rifle was an old-world hunting piece, featuring (usually) heavy rifled barrels and flintlock ignition. Historically, they were the first readily available firearms to feature rifled barrels, and the rifling was created initially to provide a place for powder fouling to collect between shots. The first rifling was "straight" with no twist and quite large by today's standards, featuring grooves and side channels in the bore that equaled or exceeded the cross-sectional area of the bullet. Sealing of the bullet to the bore was non-existant, as was accuracy or transmitted energy.
Someone, who was probably sloppy when making his rifling machine, induced a twist into the rifling, and discovered that a tightly patched ball could be guided by the rifling, increasing accuracy, muzzle velocity, and transmitted energy.
Immigrants from the German principalities (there was no "Germany" is those days, just city-states) brought these rifles, and the ability to make them, over to the new world, but found the heavy rifles cumbersome for use in the vast wilderness that was North America. American gunsmiths, mostly in Pennsylvania, turned their talents to making a lighter, but just as long-barreled, piece that was better suited to the woods of eastern North America. Lock, stock, and barrel became lighter, producing a uniquely American style of firearm.
The actual "Jaeger" rifles were not built in North America, at least not in any serious quantities. Almost from the beginning of domestic firearm manufacture in North America, the lighter "Pennsylvania" rifle was the norm. I am defining domestic firearm manufacture to exclude those guns manufactured from parts imported from England or a German source, although locks were imported for quite a while, before gunsmiths began manufacturing them locally.
Fred
Warm and spring-like in Eastern Missouri