Does anyone use
Think about it for a second:
Let's assume it works. Now, what benefit could a 1% velocity increase provide? That's less than the typical tolerance on the claimed velocity on a box of new shells, and reloads are typically less consistent than facory. So, if the third and fifteenth shell in your box aren't withing 15FPS of each other, what good would it do to have both of them shoot 15FPS faster?
If you want an extra 15FPS, run a hone thru your powder bushing for five seconds and be done with it.
-Gary