I Shoot a browning rage 78# draw 27.5 i shoot a 2512 xx78 arrow with broad head total whieght 501 grains i also some times shoot carbon staxis arrows totaling 479grians out of these am i getting 300fps at any?
You are only getting about 230 fps. The IBO on that bow is 295. You would get 295 fps by having a 30" draw, 70 lbs, and a 350 grain arrow. If you want to shoot 300 fps you need to pull 70 lbs, 31" draw, and a 350 grain arrow, or you can pull 80 lbs, 30" draw, and 350 grain arrow. Either way, you won't get 300 fps with that bow.
I would agree with the others. Based on the bow's advertised IBO speed rating, your draw length and arrow weight I think 220-230 to be a fair estimate.
I plugged numbers into a program I have for 350 grains, 295 ft/sec, 70# peak, 8" brace and 100 grains of virtual mass and then given those initial conditions changed the peak weight to 78#, mass to 479 grains and draw to 27.5". The result was 257.0 ft/sec.
In order to get 300 ft/sec for 479 grains and 27.5" draw I had to take the weight up to 106.3#.
300fps?
