Whitworth brought some factory .454 loads to shoot. I looked at them and asked why the crimp was so hard. They were REALLY crimped.
Boolits pulled like crazy when we shot.
None of my hand loads pulled at the same pressures and velocity.
I have trouble with an extremely heavy boolit in another caliber, I don't know how to hold the weight unless you pin the boolit in the brass. Can't beat inertia with any brass. There is a limit and crimp will not help.