I have lots of speed loaders - the McFadden device I had to modify by making the receiver shorter and wider to work with my SR22 magazines.
It is a bit bulky but I like it.
another option is a bit more portable and comes with a lanyard so you don't lose it and it is readily available is the Brass Stacker - Ruger SR22 Magazine Loader :: Ruger™ Platform Products :: Brass Stacker™