[Unclenick]

I've found a number of old cases over the years that had mud insect nests in them. That mud is glued in place by insect saliva, so you often need a soak in water or even hot water and soap to clear it. During the case inspection stage of the reloading process is when you are supposed to catch these. That's the step between cleaning and actual reloading where you look the cases over inside and out. I fear that progressive reloading causes many to skip this step or just glance as they insert another empty. One plus for the progressives is if they have a fifth station for a powder level checking die, it will catch these automatically.

I once had a .30-06 LC case I brought back from Camp Perry, having fired it as new ammo myself. It felt "funny" when I picked it up. Looking inside revealed the bottom was dark, but then, so is carbon deposit, so I wasn't sure I was seeing anything. But it didn't balance right, so I weighed it and found it was about 35 grains heavier than the rest. Poking a stick in did nothing. I finally took a dental pick and succeeded in peeling a flattened lump of lead off the inside of the head. It must have been bullet core metal that got in with the bullets and fell into the case and worked its way to the bottom during transport. Not enough volume to cause a pressure hazard with the load LC put in, but I was glad to have it out before I put a hand load in that was nearer maximum.

Always look. You never know what you'll find.