My wife and I picked up 17, 8 with a 2200, 9 with a 2100, both with 11" mono coils. Smallest was about the size of an olive, don't remember the weight. Some were very loud, others were very faint, the faintest, oddly enough were near the surface, the deeper ones were quite distinct. All were strongly magnetic, and were in an distinct impact area. We gridded the area, and the absence of smaller fragments causes me to suspect that some were missed. During the time we were there the most pieces were found with a Minelab Gold Striker.

Keep looking,

GaryG