I bought several 1000 of the new Cheddite paper hulls, in 16 gauge, from Graff's. I load them with SR-7625 powder, at around 1150 FPS at 7200 PSI. Every hull gets brittle and burns through, or breaks off, at the brass some where between 3 and 5 reloads.
I just figured it was due to the thin wall of the hull.