The Ram Prime works very well. Mine came with my Hand Press, so I've had it quite a while. Excellent feel and low effort required. I don't use it much, because I have an Auto-Prime, which is dramatically faster for me. The exception is that I use the Ram Prime on my WSM and WSSM cases, because the Auto-Prime is too narrow to get those wide cases in without grinding some metal off. That's ok to do, but it's not like I shoot thousands of WSSMs so I just use the Ram Prime for that.
