Rear Brake Adjustment

Over the winter I converted to disk wheels. Part of the "might as well"s in
the project included new rear wheel cylinders, adjuster bolts and brake shoes.
Now, however, I seem to run out of adjuster bolt travel before I get the
adjustment correct. The adjuster bolt is visually equivalent to the original
item, the shoes are installed correctly according to the Bentley, and the
system has been bled. Do my drums need replaced? Any other helpful ideas?
David Lieb