I use a Lee turret press, and I have never had a primer go in sideways, but I have had a coule go in upside down, but the only way they can do that is if I didn't get ALL of them flipped over when I started. Not the presses fault. One time I did fire off a primed (no powder, no bullet) 9mm in my garage once to see how loud they really are. Man, was I surprised! I actually went in the house to tell my wife that I was okay. I think the neighbors were surprised also. (I live in a very quiet neighborhood, and had the garage door open when I fired it off.) They definitely pack a punch....