[Smokey Joe]

Sasquatch--Nickel plated brass is more brittle than straight brass. I shoot bullseye, and load all the brass I can get my hands on. The nickel plated cases just split earlier in their reloading lives than the all-brass cases. They are usually good for several reloadings before they split, and if they were free range brass to begin with, this is a Good Thing.

Exactly why nickel-plated brass should be so I leave to the engineers and metallurgists. But you hear the same thing from just about any pistol-ammo reloader you ask.

Renaissance7697--Guess yr Dillon just doesn't like R-P nickel-plated brass. I'd use something else were I you.

Unless you actually like exploring the vast, unanswerable questions of the universe, there's no percentage in fiddling with the "whys" of things like this. After determining that a thing does not work for you, you get an alternative, get it to work, and get on with your life.