So, I was just trying to silver 10 of my crossbow bolts and it wasn't an option.  I can silver my crossbow but since I am not planning on hitting the monsters with the crossbow itself I don't think that would help very much.  Does anyone have a workaround?  I changed the item name to silvered crossbow bolts and then reduced the count to 10, but when I added more crossbow bolts it automatically added them to the silvered bolts in my inventory.

Create a custom item (in manage inventory tab) named silvered crossbow bolts.

Ammo is in a weird mostly but not completely finished state. It doesn't come up often. Hopefully the inventory revamp will polish ammo functionality (things like showing up on actions tab and magic ammo applying modifiers), but I'm not holding my breath.

Renaming an item doesn't change the item, so if it is programmed to stack, it will stack.