Re: Questions for S1, brass preparation?
Go to p.256 in Vaughn's book for sketches. The ear phone diaphragms are the hardest thing to find. You have to make a tube for each individual bullet type, and the lighter the material the tube is made of, the better it works, as long as it is rigid enough. Harold shows the radial holes through the centline, they can not be or it wont spin. He also shows the holes set at the cg of the bullet, we got better results by placing the holes .020 above the cg, closer to the ogive.
If you play with the clamping point at different spots on the tube and vary the air pressure, these things can work really slick.