SR22 mags have a follower button, just push down on that a little and the rounds should go in easily. I shoot enough that I use a Hilljak loader to push the button down (as my thumbs would get a little sore over the course of shooting 300 to 500 rounds at a range session). My Mark IIs are easy, just push the button all the way down and drop the rounds in. The SR22 is a little more finicky, because of the slight stagger in the mag, so you have to push it down a little for each round. If you push it all the way down, like the Mark IIs, the rounds can turn as they drop in and not stack properly.
Hope this helps.