I had a second chance to shoot the SB1 357 mag/ now max.
The first time around I got a couple of pierced primers with 38 special factory loads (Fiochi) so
I pulled all the bullets (125 grain jacketed) and replace with 125 grain cast. No more pierced primers
from that batch yet.
Then tried 357 Max handloads. 180 Hornady xtp with winchester small rifle primers and alliant 2400.
When I got to 14 grains (1400 fps) I got a pierced primer. Then I got another at 15 grains (1565 fps).
What has been found to be the problem in the past with pierced primers and the 357 on shotgun frames?