I Whisker's book, GUNSMITHS OF VIRGINA, it says this about Jacob Entler:
Gunsmith. At the sale of the estate of Martin Sheets, on 19 February 1808, Entler bought a gun boring machine, five gun barrels, a lot of cherries to make bullet molds, and miscellaneous gun stocks and other parts. Entler died before November 1822 in Jefferson County, (West) Virginia, and his estate inventory showed some of these same materials, including the boring machine (Jefferson County Estates). The same information is listed in GUNSMITHS OF WEST VIRGINA by Lambert and Whisker. Hope this helps.
Gibster.