I shoot a 42# @ 30" Blacktail TD and it likes a 32", 2215 aluminum arrow which weighs 619 grains. It's very flat shooting out to 20 yards with very little drop. I think it's very flat shooting because most of the weight isn't in the point weight like with wooden and carbon arrow shooters. It's spread out over the entire length of the arrow.
A 2215 aluminum shaft weighs 10.7 grains per inch (32" times 10.7 grains equals 342.4 grains), the RPS insert weighs 30 grains, broadhead and broadhead adapter weigh 215 grains, super uni bushing weighs 9 grains, the Super Nock weighs 13 grains and three, 5" parabolic feathers weigh 9.6 grains.
Since the heavy weight is distributed over the entire length of the arrow, instead of just at the tip with many wooden and carbon arrow shooters and with the long working limbs on my 66" Blacktail, with it's 19" riser, it casts this heavy aluminum arrow with lots of speed and very little drop at 20 yards. My FOC is 17.5% and it also gives me 14.73 grains per pound.