I just purchased a DS-10 SWCH speedloader for my S&W 617. Works great! Easy to use (never fails), seats the cartridges fully every time, compact, tough (made of a hard plastic, but hey, I'm not in combat), and best of all, only $15 plus $7 shipping, so $22 total.
Website for purchase:
DS-10-SPEED | Speed loaders for 10 shot S&W 617, Ruger GP100, 8 shot S&W, Ruger LCR, made in the USA .
Give it a try!
Skeet200