Been awhile since Ive owned a D-style bow, just traded for a Northern Mist Superior 51@27, Im drawing it 28 1/4 or a tad more...believe the string is a FF string of some sort not sure what, also have B-50 string for it...what aluminums or carbons should work at this draw length, tried 29.5 in. 2016`s w/260 gr. up front, arrows hit dead center but fishtail back and forth a little, 35/55`s same length w/280 gr. up front a little better but still not right. Brace is 6 1/2 in., played with it from 6 1/4 up to 6 3/4 and arrows still fly the same.
Have you tried to lighten up the point weight and see how they fly? Do they bareshaft good? For me I'm not all that convinced that EFOC works that good for aluminum,it can for carbon because they recover from paradox so much quicker.
Tried 125, 145 and 175 gr. points and they still wouldnt fly.. did try some 70-75# super cedars 30.5 in. w/160 points and they fly pretty good so maybe it wants a little heavier spine.. havent done any bareshafting yet, it was 28 degrees out and was just trying to see what would shoot decent..have to be a tad warmer for me to mess w/bareshafting.
In my Northern Mist Baraga I have been shooting 29" 2016 with 145 points. My bow is 55 at 27" and I draw 27. They fly good out of my bow.