So, the 'fact' that tight crimps are necessary for pressure to build and assure good combustion when using slow burning powders has been refuted? The Hartin crimp with half the fold crimp cut away would seem to be the very definition of a soft crip - overshot card or no.

Loading at the low pressures that you guys do with the low burn rate powders should, according to conventional wisdom, result in nothing but blooper city without a tight crimp.

What's the deal? Is conventional wisdom as passed down by generations of reloading experts wrong - again?

"The price of good shotgunnery is constant practice" - Fred Kimble