I used Federal small pistol primers, .38 Spc. brass and Radians foam earplugs. I think that the earplugs are too big for use in the .357 brass and bore. I loaded twenty rounds, two earplugs exited the barrel. Two failed to exit the brass completely, all the earplugs were too damaged to be reused. All the primers bulged and showed signs of over pressure, as primers were only propellant no damage came to the firearms.
Next experiment will be with .44 brass, but those guns are all in storage so it will have to wait. Also it looks like I have lots more large pistol primers than small pistol primers. If I can find my CCI 550s, I still have reloading stuff in at least three places, and I can find some smaller earplugs I might try again with .38 spc brass.
When my camera card finishes down loading to the computer I will post some pics up.