DRIFT:
Is the continual deviation of the bullet in the direction of the rifling. About one minute, i.e., one inch per 100 yards, must be allowed for this at the longer ranges in sniping.
Other Definitions:
SUPERFICIAL FOULING:
The fouling that appears in the bore immediately after firing. It is then quite soft and easily removed, but if allowed to remain, it becomes hard, difficult to remove and, by attracting moisture from the air, begins the rusting process.
INTERNAL FOULING:
Fouling that actually gets below the surface of the metal when firing; this gradually sweats its way to the surface and should be removed as it appears.
(Note:—If cleaned with really boiling water, the pores are reopened, internal fouling is removed, and thus the cause of sweating is done away with. The Barrel must, however, be dried immediately, or the cure will be worse than the complaint.)
CORROSION:
Is the black pock-mark or indentation left in the bore after removing rust.