After 60 years in industrial work ,I learned long ago to keep eyes clear of possible blasts.........I have never been worried by primers going off in a press,or a impact puller ,for that matter.........primers going off when you reload fired berdan 303 cases wasnt that rare,due to the ocassional deformed anvil........when I was young I used cut off 303 cases in a 44/40, they were reloadable,and the Winchester brass wasnt.......because I had no primers,only 303 berdan surplus primers.