Have my doubts about your theory of constantly and rapidly sinking pellets.
I didn't see where Stan said that the downward migration or sinking of those heavy dense lead pellets was "rapid".
I wasn't going to comment when I saw your post last night. It seemed obvious that you have your mind made up, specific gravity of lead, and the non-stop efforts of anti-gun and anti-lead ammunition advocates be damned.
But let's look at an even denser metal, gold. There is a reason why the vast majority of gold is found well below the earth's surface. Like lead, whether it is molten or in solid form, over time, it sinks. Free lead is seldom found in nature, so gold is a good example. The small amount of gold that is found on or near the surface is typically from meteorites, or blasted to the surface during volcanic activity. Being so dense, it immediately begins to sink into the earth, or is washed into creeks and rivers where it again falls into cracks or depressions in the rocks or bedrock.
This is the same reason that artifact hunters search for ancient Indian arrowheads and spear points in plowed fields. Over hundreds or thousands of years, most tend to sink into the soil, since flint is more dense than soil. Plowing brings them back up to the surface, and the rains wash them off and make them visible for a while... until they move back under the surface once again. Frost heaving may also bring up rocks or flint artifacts, etc., but these will also sink again over time.
I'm pretty sure that you will not be convinced by any number of examples. That's OK, so long as most people understand. Fishermen learned long ago to use light wood or hollow plastic for bobbers because they float... and they use lead for sinkers and jig heads because they sink. I know that density thing is a pretty tough concept to grasp... do you perhaps have a brother named BrentD?
