In the late 17th century to the early to mid 18th century, short to very short Jaeger Rifle barrels were swamped to make them handier, even though very short barrels may not have needed the swamping as much as the long to very long rifle barrels used in Germany, Switzerland and here in the colonies.
I believe up through the Eighteenth century that long rifle barrels were swamped both for the larger calibers used in much of that century and especially the longer length of the barrels. We sometimes forget that rifle barrels often went from 44-48 inches and some as long as 50 inches, like the one Spence showed above. Swamping the barrels made them lighter and more manageable, especially when swinging on a running target. It would be hard for me to imagine how muzzle heavy and “dead feeling” a straight barrel would be in 44-48 to 50 inches. Of course, the extremely long barrels were at least partially due to the mistaken old myth that black powder burns throughout the length of the barrel. This even though the Royal Society of London proved that was false in the mid 18th century, though that myth surprisingly continues to this day in some quarters.
I have a late 18th/Early 19th century reproduction long rifle with a 39 inch, .45 caliber straight barrel and it is a bit too muzzle heavy for a rifle carried and used all the time, though the added muzzle weight feels good for an offhand target rifle. I shudder to think what it would feel like with a 44 to 48 inch barrel and having to carry it all the time.
Water powered Trip Hammers were used to forge large quantities of barrels by German, British and other Continental Barrel makers from the 17th century onward. For example, the extremely cold winter of 1739-40 in England froze up the streams and rivers in England so badly those water powered trip hammers were “stopped cold” and they had to order huge quantities of “Dutch” Guns and Gun Barrels that year and for the next two years. The quantities were something like 36,000 muskets and 10 or 12 thousand separate barrels in that three year period. This during the “War of Jenkins' Ear” that morphed into the War of the Austrian Succession circa 1739-1748. Of course, there was no market for such large quantities of gun barrels here in the Colonies until the AWI and later, even IF the British would have allowed that large scale of Industry here in the Colonies.
Though much or most barrel shaping and swamping was done while the barrel was forged, both German and British barrel makers used very large to extremely large files known in the period as “Rubbers.” These used to shape or “rough swamp” the barrels before finer files were used. Some Rubbers shown in German Gun Shop engravings are downright huge and were obviously meant to be used by two men. Rubbers even occasionally show up in British Military Artificer’s/Armorer’s lists of tools sent here during the F&I War and AWI, though obviously not intended for swamping rifle barrels. Though I have not been able to document the use of Rubbers by American Gunsmiths, I doubt most people doing the Probate Inventories of Gunsmiths would have known that is what these large files were called. Most Probate Inventories for Gunsmiths only identify some or very few of the tools by name. Other gunsmiths would have known the names of the tools, but not the average person doing a Probate Inventory.
The 19th century saw the trend of barrels getting shorter and thus did not need to be swamped as much. Even so, many of the barrels that looked “straight” were tapered, to ensure they were not as muzzle heavy.
Gus