I've dropped in the Butler Creek .17 HMR conversion (with stock) into my 10/22M. Simple replacement of the barrel (and stock). .17 HMR will fit in the 10/22M mags. Mine did hangup in the middle of shooting. I had encountered a fellow .17 HMR shooter (his rifle a 77/17) before I got the conversion who also had his mags hang up.
The solution to the problem is to loosen the bolt that hold the mag together a tiny bit. My mag now functions flawlessly with .17 HMR.
I have encountered some stovepipes but attribute the problem to a still relatively new gun (no more than 200 rounds of .22 mag run through it previously).
Had the best results with Hornady and Remington ammo (V-max) - 1-1½" at 100 yds. Not so good with CCI and federal hollow points - 2½-3" at 100 yds. I could propably do better with the Horn and Rem with a better scope than what was on there.
Over at rimfirecentral, there are a few who have done conversions with 10/22 (.22 lr) to .22 mag and .17 HMR but the gun requires some involved modifications. Also, conversions using 77/17 barrels to 10/22 and 10/22M, also not straight drop-ins.
77/17 mags and rings will fit the 10/22M, they are the same part numbers.
EDIT : Please note, 10/22M = .22 mag.