is the famous nitro
and powder solvent
invented by Frank August Hoppe
in the early years of the 20th century
when the arrival of (the then corrosive) smokeless gunpowder
came about. The need for an effective cleaning solvent was great as the corrosive ammunition
could render a barrel useless in no time.
His educational background in chemistry helped him in his formulation of the 9 chemicals that was used in cleaning and rust protecting rifle barrels. This secret formula proved to be very effective in cleaning powder residue and getting rid of lead and other metal fouling thus extending the usable life of the rifle.
Today, Hoppes is known for providing excellent products for the shooting crowd, including civilian, sporting and even law enforcement. These products range from the famous #9 to bore brushes and other such accesories.
It is also a point of fun making that if one wants to attract a gun enthusiast, one only has to rub a a few drops of Hoppes #9 behind one's ears and surely you will attract gun lovers like bears to a pot of honey. Hoppes #9 has a sweet smell similar to that of banana extract but is not quite, to fully experience buy a gun and learn to shoot, afterwards clean with some Hoppes #9.
Hoppes #9 contains kerosene as indicated by the label but the other 8 ingredients are top seekrut and is supposedly unchanged from the original formula. You will know if the barrel of your gun is clean if you soak a patch of cotton cloth in Hoppes and run it through the barrel and you no longer see any discoloration. Lead and copper will leave a dark greenish blue stain and powder residue will leave black soot.