Semi auto .17 HMR pretty much no longer exists. I've never heard a definite reason as to why, but you won't find one.
Savage is usually the way to go. They feel good, the bolts aren't sticky like the Marlins can be, adjustable trigger, lots of options starting from about $250 new.
But as a heads up for anyone thinking about a .17 for hunting, or more than just "Its all thats available." There is a new .17 Winchester Super Mag that will be hitting the market this year. Savage is making a rifle called the B-Mag that will be the first to be feeding this ammo. MSRP is $350 for the rifle, ammo is said to be about the same as the HMR.
Still a rimfire, but is going to be reaching up to 3,000 FPS, and will also be able to use a 25gr bullet (~2,600 FPS) Savage rep told me there is very little drop to 200 yards.