I have to disagree with you Peter.
As you know, I keep and breed Amm, and I have a lot of Galtee Bee Breeding Group genetics in my stock.
In May many of my colonies are quite happy to work up to 15 or 16 frames of brood when the second brood chamber is added.
They don't fill the upper chamber entirely with brood but are quite capable of filling half with brood and the rest with stores.
I grafted from a pure Galtee queen yesterday evening and it had at least 16 or 17 frames of brood.
I also find a pollen arch above the brood is quite typical.
I think that is common to all subspecies of bee.
You must be seeing what you have selected for in your own stock over the years.
A lot of the lore about Amm comes from the Beowulf Cooper books such as 'Honeybees of the British Isles' and is perpetuated to the present day by Bibba (UK bee inprovement group) There is not a jot of science or experimentation in any of Cooper's books and they are merely one man's observations and opinions about the stock he kept at the time.
There are many claims about Amm which can only be traced back to this one writer which do not appear anywhere else.

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