Only had 1 cartridge where the Lee collet crimp die was not enough. The .450BM (and the .450 Corvette of course). I ended up modifying the Lee die and basically did a light double ring crimp. We had called it a "stab crimp" but it was not a point, nor a rectangle, so stake crimp and stab crimp it technically was not. But in the same relative location one would place a stab, or stake crimp. The collet portion was machined shorter so that the crimp would be placed under the case mouth in the actual neck. It took three steps, first take out any flare, then the first crimp about 0.15" below the case mouth, then the second about 0.3" below the case mouth. We found two lighter crimps to be superior to one heavier crimp in terms of accuracy.
I have always said I was going to do the same thing with my .41 Magnums, but have still not gotten around to it.