Well (you're not going to like this answer) it depends - some use larger grits and lower pressures and some (like me) use finer grits and higher pressures. I use 240-320 at about 100psi and then use a plastic wool sponge with gun oil to rub it down. A gunsmith that has down a couple of my rifles gets a very fine finish use 80-120 grit beads I believe at about 50-60 psi. The glass bead actually only peen the surface - silica sand and aluminum oxide will actually break-up/rough-up the surface. If you're not going to coat the barrel, I would use glass beads.
Right on the money , offshoreman . It's downright refreshing to see someone give advice , that actually knows what they are talking about !
