|Damage vs. small||1d4|
|Damage vs. large||1d6|
Along with other cursed missile weapons or launchers, cursed bolts occasionally "slip from your hand" when you throw or fire them, and end up on the ground.
Along with arrows and darts, crossbow bolts are liable to break when fired or thrown. This destroys the item, with no message. The bolt simply disappears. This chance to break is minimized by the item's enchantment and your Luck. Compare this with daggers, which cannot break when thrown.
Projectiles have a probability of disappearing after use. For uncursed projectiles, this depends on the net enchantment/erosion of the item. +0 projectiles have 2/3 probability of disappearing, +1 have 1/3 probability, and +2 or greater reduces the chance of breaking to 1/4 probability.
For blessed projectiles, there's an additional possibility of being saved due to luck, as follows:
Luck prob of save 0 - 2 .25 3 - 5 .49 6 - 8 .74 9 - 12 .98