Lapping is a machining operation, in which two surfaces are rubbed together with an abrasive compound between them, by hand movement or by way of a machine to remove machining irregularities, and to reduce friction between the parts.
Lapping can be done a single part to smooth a particular surface or, it can be done to mate and smooth two parts to each other. Engine valves to cylinder head or firearms slide to frame are common examples. The parts are usually slightly oversized and the lapping removes minuscule amounts of metal in a controlled means to achieve a tight fit with a polished and smooth operation of the parts.
The 2nd Amendment was, and still is intended to protect the individual citizen from Tyranny. Whether that Tyranny originates from
our own Government, common criminals, Progressive Liberalism, or foreign invaders, is irrelevant.