The 17 rimfires are shooting a real rifle bullet not a chunk of lead shaped like a bullet. The 22 mag can be very accurate as it is also a true bullet design but not in the class of the 17. More on the order of a pistol bullet. There is a new bullet for the 22mag of the same design as the 17. I have not tried them yet but have heard of some good accuracy reports. A lot depends on the individual rifle. I dont know if the traditional twist for the 22mag is optimal for the new bullets. Some of the 22mag rifles had tube feeds so bullet design was safety inspired. I believe a 22mag designed around the new bullets would be comparable to the 17hmr in accuracy and almost 2x the bullet weight. That would give it a big advantage on larger varmints. I am thinking of getting a 22 Hornet which I can load.
"I would not be an old man if I had not been an armed young man." JTJ
Patron Member NRA
"As democracy is perfected, the office of President represents, more and more closely, the inner soul of the people. On some great and glorious day the plain folks of the land will reach their heart's desire at last and the White House will be occupied by a downright fool and complete narcissistic moron."
--- H.L. Mencken, The Baltimore Evening Sun, July 26, 1920