>but remember that left to their own devices, the bees will make about 15% 
drone comb

Technically I'd agree with the above statement as a generalization, but 
there are lots of exceptions, especially if we're talking about 
interspersing frames into an already established brood nest.  "Left to 
their own devices" bees don't move combs around, and they DO tend to build 
most of the brood nest from nothing after they first swarm.  So in 
practice, if we're talking about interspersing empty frames into an 
already established brood nest, especially at a time of year when the 
brood nest is naturally wanting to expand, I'm pretty suspicious of the 
15% figure.  Under those kinds of circumstances, I think 30, 35, even 40% 
drone comb can be realized.

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