Infernal Bolt

Infernal Bolts have the 2nd highest attack of all ammunition available for crossbows in the game (only beaten by Spectral Bolts). These bolts are not available from NPC stores, thus their price depends on the game world economy. The easiest way to get them is by asking an experienced blacksmith to craft 3 bolts from a single Soul Orb. Historically, these bolts were seldom used due to sparsity of the material. Nowadays, on older servers there is an abundance of soul orbs coming from places like Roshamuul Prison being a popular hunting destination among higher-level characters. If obtained in large quantities at NPC buyback price of 25 gp, an infernal bolt effectively costs as low as 8.5 gp each. Such a price tag places them cheaper than weaker Prismatic and Drill Bolts, thus making them a very affordable ammunition in terms of cost per damage, beating Crystalline Arrows by a factor of ~2.5. You can exchange Soul Orbs for Infernal Bolts through the The Sweaty Cyclops Quest. Each orb turns into 3 infernal bolts. You can obtain 100 Infernal Bolts in The Ultimate Challenges Quest Warlord Level.