This is a mag loader I designed for the PSA U9 magazines. They are similar to the scorpion magazines, but different enough to not work well (if at all) with the loaders I found. I also included a round stripper on the back that rides between the mag lips and strips out the top round. 

This loader has a nice shelf for your thumb to pull on while you load the mag so you can use your finger on the top and thumb on the shelf to push the rounds down. Lots of mechanical advantage to power through those last 10 rds with ease!

Push down, slide the round in, lift up and slide the round to the rear. I also found it easy to lift the loader up and rock it back to push the round towards the back. That might take a bit of practice, but it worked well for me. Let me know if you get it down, too!