But if you do insist on using a press, be sure to wear safety glasses. Better yet, a face sheild. Also, long sleeve sweatshirt might help to protect your arms.
Say WHAT? For why?
Ever actually look at a decapping die? The case is entireally enclosed by the die, if perchance the primer EXPLODES the primer cup and anvil are going to exit the bottom of the presses ram. Nothing is going to fly out up across or anywhere else. Its a primer, not a bomb.