The original short barreled rifle is called a "Stutzen", which has its "origins" in Austria, southern parts of Germany and nowadays Switzerland. All famous southern german gunmakers "Kuchenreither for example" mostly built "Stutzen", unless they spezialized in pistols. You may refer to a "Stutzen" as a jaeger rifle, but that would be too short-sighted. There were early german rifles with long barrels as well, a lot of them half-stocks and they look more like a rifled fowling gun thus the longer barrel was not an invention in the colonies. From the number of guns built with longer rifled barrels, they were more commom in the colonies.
Usually cavalry muskets were shorter, but they were usually not rifled.
A good site to check some ancient guns out:
http://www.bolk-antiques.nl/index.cfm?page=collection&cat=1209&subcat=2185&catname=Antique