I have'nt had a whole lot of experience with semi autos. The ones I have had were picky about the type of ammo they liked, the temperature it was and what lube you had in it. Some wouldn't cycle at all in the cold unless they were totaly clean and dry (lube free). I like levers. THey are real fast on the repeat and work in any weather. I have both 22 and 22 mag levers. My 22 is a old 39A pre micro groove Marlin and the mag is a Win 9422M. The mag is actually less accurate. I take game at 100 yards with both. The mag is much more lethal but the ammo costs 5 times more too. Had a buddy who had a beaver problem on his place. THe mag did a real job on them, one was almost 50 pounds. Not the biggest beaver I have seen but the mag plowed right through shoulders, spine and a couple inches of fat on each side and exited on all three beavers. I wouldn't be afraid of a 17 HMR but the ammo price is still near 10 bucks for fifty here. Thats TOO much IMO. I can get 223 center fire for less. I did penetration tests with 22mag versice 117HMR in dry bundles of catalogs and was pretty impressed with the little 17 considering it only had a 17grain bullet. It just could not out penitrate the 22 mags in 40 or 50grain,, be it solid or hollowpoint.