What size broadhead to reduce spine by 20-25 lbs

[Heavysquirrel]

I have canebrake 62# @ 28"

Say that shafts are spined at 85 # @ 28 "
 At  26 " draw what size tip  would it take even though they are 28 " long.

I think this makes sense
Also the shaft weigh around 900 grains --will they drop like a rock out to 25 yards

[yamapup]

Time for new arrows, I think. Proper arrows are too important, to try to make do. your draw weight must actually be about 57# and it is unlikely that you will get satisfactory results with the arrows you have. With wood arrows, you are out of luck! If you are shooting alums or carbon, you can get screw in points up to 250 grains. Do you really want a 900 grain arrow?

[Aeronut]

I make and shoot some bamboo and cane arrows with a 160 grain head from my 53# BBO.  None of these shafts have spined under 90# and fly great.

Dennis