The Hornady priming system primes after the end of the downstroke. Pushing the lever forward engages the primer punch, seating the primer. This is another unique Hornady feature, because you can cycle the press without it automatically engaging the priming system. If any powder grains get inside that primer punch, it stays stuck open or permanently engaged. On the upstroke, the primer transfer bar will not be able to move, so the press will bind. Don't force it, or the transfer bar will break. In that scenario, disassemble and clean.