Its just interesting that in "Successful Queen Rearing" by Spivak she has a picture of cell bars with 3 rows of 20 cell cups(they are spaced 3/4" on center). Spivak mentions a properly prepared swarm box handling 60-100 cells. I wanted to fit 20 in one row since the Mann Lake queen hair roller cages won't fit two deep on a medium frame. Thanks to all for the info.

60-100 ha! if I meet her and she says that same thing I would have to ask her what she is smoking from a queen rearers stand point because more than half probably want be good queens, I know she is a pro at it but its like every other pro that says over 40-50 in a cell builder is all one should load with cells, a hive might can raise that many but how many will be good quality? I think it is Charley Harper that says for the best chance at quality queens use a queen right cell builder and only load 15 grafted cells the first day then 15 more the second day on 2 different cell frames (just using the top bar) to insure the best queens you can raise. now what I mean by the best is top feed queens and none under feed to insure this, the queen can live and deliver to her potential if mated right, you can always have some you raise that might not be right from the start but this way gives her every chance she can to be a very good queen. guest since he is in the Russian queen breeder association and sales his queens at top dollar he uses this method to have the best queens he can raise. now this is a man that has 400+ hives and works them alone.
but like Robo said
Why use hair rollers? It is much easier to let them hatch in mating nucs and not deal with introducing them. I agree 100% , it is so much easier to have a nuc ready to install the cells in than introducing one.