Complex sentence: The single most famous Deringer used for this purpose was fired by John Wilkes Booth in the assassination of Abraham Lincoln, although Booth's Deringer was atypical in that the rifling twisted counterclockwise, rather than the usual clockwise twist.
Split into simpler sentences: The single most famous Deringer used for this purpose was fired by John Wilkes Booth in the assassination of Abraham Lincoln. Notably, Booth's Deringer was unusual in that the rifling twisted counterclockwise, rather than the typical clockwise twist.