Against Ascended, they are roughly equal to level 80 bolts. Against anything else, they are level 50. Damage is calculated starting as if the bolts were simply bronze, then adding a random amount approximately 460 (or up to 720 damage against Ascended) to each hit. This makes the hits rather lower than expected from level 80 ammo, but they're more consistent. They require level 50 Ranged to use. They are single-use and are not retrieved by Ava's devices. Fragment bolts are not kept on death.