RhinelandArms,
I relined two used 10/22 22lr barrels I got from the EE, one is chambered in .17 Aguila and one in the 17Mach2. The 17 Aguila works great in the 10/22 with just some weight added to the bolt handle -- the 17Mach2 required a little more work but it shoots really nice too. I didn't try the Aguila at the range yet but the Mach2 will shoot 0.5" at 50 yards using a 3x9 power scope and most likely can shoot even better. Both rounds work really nice in the ruger magazine but I know the Aguila won't work in one of those hi-cap mags but I have not tried the Mach2 in a hi-cap yet -- having too much fun just the way things are now! I read that the 17 Aguila can be fired in the 17 Mach2 chamber with little loss in accuracy so I tried it. It's kinda strange -- the Aguila will shoot in the Mach2 OK and the cartridge doesn't get fire-formed out for some reason! The accuracy was not as good as with the Mach2 round.
EDIT TO ADD; I tried the same thing you did and stuffed a 25 round Butler Creek mag full of .17 mach2 rounds. it seemed to work ok for the first 4 or 5 rounds then it started jaming. Seems that as the rounds are loaded the nose starts to tip down and they don't come back up as they reach the feed lips.