Currently making my own "all flock" with a mix of 1 part layer (16% protein, 3.5% calcium) to 1 parts Game Bird Grower (24% Protein, 1% Calcium), with oyster shell on the side. As you can see from my sig, I have quite the variety in my flock - though I've now culled all but one rooster and several drakes (last duck incubation was 0%), but will be culling drakes regardless for the holidays.
/Edit Previously used the Nutrena Flock Raiser Pellets, and the Purina All Flock when I couldn't get that. Local mill is cheaper and fresher, which is why I changed - I buy 200# of feed at a time. Should probably buy 300# of feed each time, and further reduce my trips into what passes for civilization.
Also, my birds supplement by free ranging over about 3.5 acres set aside for them, with a mix of grains and forbs - though they largely keep to an area about 1/2 that size)
/edit and there is still more calcium in my "all flock" than I want - when the next batch of chicks are hatched, and most of the drakes are culled, I'm going to alter the mix again. Shoot for Protein at 22%, Calcium at about 1.5% - 3 bags GBG, 1 bag Layer, Free Choice Oyster, and watch how fast my male dual purpose bulk up. If it is cost effective on greater growth vs greater expense comparison, I'll stay at it, if not, not.