FWIW, I recently replaced the outer recoil spring, and installed new heavy duty mag springs as well. It had no effect on the appearance of the handloads with CCI primers (which were still flattened and sheared). Also had a few failures to fire, possibly from blocking the firing pin hole in the breech face with sheared-off primer material.
Primers of Winchester White Box value pack ammo look like WS6's pictures above, except maybe the firing pin indentations are a bit more elongated. In other words, there is no smushing flat. And yet CCI primers are reputed to be harder than Winchester. Go figure.
