The semi-auto's in 22-mag and 17 HMR are getting hard to find, Ruger, Remington and Marlin quit making the magnum auto's a while back. There claim was a malfunction that was a danger to shooters, but I could never confirm the actual danger or issue. Just internet rumors and opinions from people who knew even less than I did.
Excel Arms still makes one (the Accelerator)
and it's a nice rifle, compact (32.5" total length), a little heavy, which I like, an 18" stainless barrel and nice feel to it. Problem is it's priced a little high and the mags are junk. I have four for mine and none of them want to work properly without some help. Even then none of them will lock the bolt open on the last shot. I'm trying to design a follower to make the magazines usable but it's slow going.
Mine looks like this minus the bi-pod and sling.