I have both Herter's ,401 brass and some made from .41 mag brass. I may have shot these over my chronograph, will go through the book tomorrow and see, if I have a chance. Of course, the Herter's .401 revolver is much larger and heavier than a GP-100, but it is an interesting round, and would probably do well in a GP-100. The .401 Herters makes a nice "mate" for my .44 Special Charter Arms Bulldog - which is MUCH smaller!
Mike Holmes
