This rifling guide is attributed to the Somerset County, Pennsylvania gunsmiths Jonathan Dormayer and Charles Monroe Knupp and is now a museum piece. It was used to produce cut rifling in the barrels of muzzle loading rifles. Charles Monroe Knupp is believed to have been one of the last apprentices of Jonathan Dormayer, was 21-years-old when Jonathan Dormayer died in 1885, and is known to have attended the vendue sale of Jonathan Dunmeyer's possessions. It makes perfect sense that Charles Monroe Knupp would have his uncle Jonathan Dormayer's rifling guide. Charles Monroe Knupp died in 1937. This rifling guide is also attributed to Daniel Border, but it is hard to understand the chronology of how that could have happened.
Daniel Border transitioned to jewelry and watch and clock making in 1855, but retained ownership of his gun shop, and had a gunsmith working in it. In 1864, John Border was working in the gun shop that Daniel Border owned, but was killed in a railroad accident. Since he was working in Daniel Border's shop, he may have been using Daniel Border's rifling guide. David Defibaugh took over and was working in the former shop of John Border a little over a month after John Border was killed, and the shop was still owned by Daniel Defibaugh. This makes it likely that Daniel Defibaugh was using Daniel Border's rifling guide. David Defibaugh died in 1914. In his booklet "The Bedford County Rifle and Its Makers" Calvin Hetrick reports that he visited Dolphus Drake at his gun shop when Dolphus was 93-years-old. That would have been about 1946. Calvin wrote that during the visit, Dolphus showed him his rifling guide, and told him it had been made and used by Daniel Border and had been purchased and used by David Defibaugh. The booklet says the purchase by David Defibaugh was after Daniel Border died (in 1891). With this chronology, if one assumes that Daniel Border had only one rifling guide, then it seems like Jonathan Dormayer and David Defibaugh would have had to own it at the same time!
The following photo shows a side view of the rifling guide. With this rifling guide, the helical path of the cutter is controlled by the twist of a rifled guide tube. That guide tube is mounted in a way that allows it to be rotated to index the cutter the angular location of the next groove to be cut.
The following photograph shows the indexing mechanism of this homemade rifling machine. The indexing wheel provides for cutting six or seven groove barrels. The pull handle for the assembly is missing.
The next photo shows the strap that holds the front of the guide tube in place, while allowing it to rotate during indexing.
The next photo shows the cutter rod projecting from the guide tube, and provides a different view of the aforementioned strap.
The next photo shows a clamp for positioning and holding the barrel that is being rifled. The clamp screw is missing.
The next two photos show the rifling cutter that is used to produce the cut rifling in the bore of the barrel.
For more information about the types and operation of rifling guides, see "History No. 13: Rifle Making in the Great Smoky Mountains" (6.1 MB pdf).
