Quote Originally Posted by Satinsnow
Okay, I have only been taking pictures for about 20 years now, but I guess there are those who feel the 120/220 situation is still nonsense, most of the time, unless you have a Russian Camera that has extremely loose tolerances, you will jam the camera or the back when you try to shoot 120 in a 220 back.

But please don't take my word for it, give it a try a few times and see what your experiance shows you..
I'm with Dave on this one. I used 120 in a 220 mamiya RB back several times, and then... kerplat! It jammed and broke. Mamiya fixed it for $120 (this was in 2000). Not worth it if you ask me.