I drill holes in shells to make bells and I love making them! I used to only buy Drimmel brand bits. I was only able to do about 40 rounds before the Drimmel bits failed. I got them for their price and am pleasantly surprised! These bits are nicely pointed and go well through the shell at first. The tip broke after 10 shots, but I was able to continue working with the now less sharp tip for a while after that. If he starts fighting you'll get another good sharp one. Generally cheaper than branded goods. These bits are good value for my needs. If you're reading this and plan on drilling projectiles, be sure to use water. Place the sponge in a shallow cake pan filled with crushed ice and water. Drill the shell into the sponge and while drilling, insert the drill bit into the sponge to keep it warm. You can even use some water at the drill site. Drilling holes is fun too. Have fun shell building!