I set off a primer in my 1050 a few weeks ago, loading .45 with recycled brass. As far as I can tell the decapper didn't pop the spent primer out of the shell in station 1, or didn't pop it out fully. Inspecting the case after detonation shows that the old primer walls were still inside the the primer pocket, as well as the structural component of the primer. I should have backed off the downstroke when I felt resistance, but I assumed it was just a hard-to-size case. Since the primer is slid forward before the punch inserts into the pocket, the rest of the nearly full primer tube was safe. My ears rang for hours (I reload in a walk-in closet) and I was scared sh*tless, but theres zero damage to the press. Now when I feel resistance at the end of my downstroke I pause and double check the case about to be primed.