The .5mm is much more superior than the 17. Dont be fooled by the .5mm's size, thoes who have not shot it nor even seen the devistation that It can do from 100-200 yards out have no idea what kind of load this little bugger is. This gun was way ahead of its time when it was introduced. Thats why they stopped production on it. This was the best varmit rifle of its time and will soon be again. My father in law has shot more than150 fox with his up untill the day they stopped making the ammo. Some of you should read the article at this site who have never seen this load or have shot it.

http://www.varminter.com/2008/5mmrrm.html