Yes, Steve, I tried one years ago to test with my .308 match rifle. Borrowed if from a guy. He swore by it.
Tested 40 loads with 4 different amounts of crimp. I gave it back after all four 10-shot groups were around twice the size of my uncrimped handloads. I swore at it.
Bart excellent comment. And since you were a member of the Palma Team, that ought to count for something.