The info that I gave you prior was my experience with dead length, and all that I had used had a cap on the end that would capture fines and pack them to the point of reducing grip. These were all of the design of say:
A Brownie, Greenlee, and Swiss type collet:
Or even a B-65:
420 max character - see page II
A Brownie, Greenlee, and Swiss type collet:
Or even a B-65:
420 max character - see page II