My buddy has a really cool buffer for his AR-15. He says it's called a Normadic Buffer. It is like a cylander the same length as a normal spring buffer. It has a PCI setting you can tweak to keep the recoil kick as high or as low as you want. He got it from a friend so he doesn't know where it came from. It goes inside the buffer tube perfectly. It is like a piston that when the gun fires it collaspes in itself when the bolt carrier is pushed back. I would really like one of these, anyone heard of this or know where they can be baught?