Yeah... don't use Vaseline (petroleum jelly). Check this link on what lubricants to use. Oh yeah, even though petroleum jelly is on maybe, don't use it. http://nerfhaven.com...showtopic=16267
Wow!! I'm impressed by how such a good job and how clean this came out. I might have to do this my self since my local Wal-Mart is having a sale on 90% of their blasters, especially the Swarmfire!
If you can't find any you may need to order some modding materials from McMaster-Carr. They do have pretty good deals there, it doesn't cost much but I'm not sure on shipping.
This is for the sharp shot. You can use craft foam, I did this and it works as well as a Nerf dart, just get the plunger and make a few twist on the craft foam and cut those circles out, then next stick them in the plunger and get a screwdriver and flatten it in the plunger so it is flush. If you use like two or more, you may need to glue the craft foam disc together with like super glue or school glue.