MP Shield 9mm Speed Loader, Refined

Of all the 9mm speed-loader clones on this site, I thought C4Matt's speed loader was clever and effective -- elegant, even -- but after loading a few mags, a bit unrefined.

Changes?

- Shrunk the outer walls a bit (smaller, but still plenty of meat to survive the abuse).
- Added finger holds to the rear (smaller, so something to hold on to)
- Added side-guides and angled back-stop on the rear to funnel the mag into the slot
- Created a short step to trap the cartridge against the front of the slot (drop the cartridge in from the rear and it catches on the step as it bounces off the end)
- Created slots for the mag's lips to slip under the trapped cartridge (step only traps the cartridge, not the mag)
- Reduced the slot length so the mag lands on the right spot on the bullet being loaded to push the stack in evenly (too long and the cartridge catches on the previous bullet instead of the previous casing, too short and it catches on the narrowed lips)
- Created shallow ramp