Just thought I'd throw this out, I put a mag spark on my T/C Cherokee and after one shot the cap got wedged against the back side of the nipple cup tight enough that I could not unscrew it with my fingers. I had to use a pair of needle nose to loosen it enough to unscrew and then had to use a thin blade knife to get the primer out. I'm not saying they aren't good to use, just saying what happened to me. Good thing I wasn't shooting at a deer.
