Made my own loader from aluminum plate and bar stock using the TK Custom Mandrel. Loading Moon Clips is a snap with the Mandrel and YouTube videos. Fit is tight and the gap allows just the right clearance for the rounds to snap in cleanly.
I’m not sure what clips to buy for all my different types of ammo.. oem worked for some ( Speer gold dot) but I bent some others trying to force in Double Tap rounds . The loading tool helps me with the right size ones but not all 357 fits