TB, my old gunsmith -unfortunately not with us anymore- was a convinced
advocate of motor oil as a gun lubricant. His reasoning was that it had been
formulated for viscosity and to work in high temperatures -which the guns he
tended to in those days attained in use, as there were more birds or they were
used in competition- as a car engine does.

JC

"...it is always advisable to perceive clearly our ignorance."ť Charles Darwin