To machine further on centerless-ground tungsten billets, including knurlning, grooving, paintig, adding logos, installing steet-tip or soft tip, and also making some special machinning design, you could get a beautiful barrel for dart. Tungsten heavy alloy is greatly used for making heavy dart barrels, which is because of its big density, and it has replaced copper to be the most popular material. The soft tip barrels are popular in 14, 16,18, 20, 22 grams, etc, which steel tip barrels might be popular 22, 24 26, 28 grams or even going up to 40 grams.