It's alot pickier with the .22lr upper than with the 5.56 upper but with a little practice it goes full auto. Problem is no range will allow me to use it so it's back yard only, which I do sparingly because the neighbors are fairly close by. You'd be surprised how much money you can spend shooting the lowly little double deuce on full auto.
I just looked up replacement magazines from one of our wholesalers and they list the same model magazine for the 75, 75B and 85. On a side note I also use CZ 75 magazines in my CZ 40B.