Caliburn Forge Darts - Steel Tip - 90% Tungsten - F4 - 21g. Introducing Caliburn Forge Darts - the expert choice for precision and accuracy. With their straight 90% tungsten barrels and ringed grip, these 21g steel tip darts provide unbeatable control and consistency. Perfect for any level of play, you'll dominate the competition with Caliburn Forge Darts. Supplied fitted with the Caliburn Replaceable Point System.