Calculate my fps w/o chrono

[M77man]

I have an 08 Diamond Black Ice and the birth cert states 298 fps with a 350 grain arrow at 70# and 29 inch dl.

My arrows should be in the neighborhood of 365 grains at 65# and a 28 inch dl.

How fast should it be shooting then? I'm going to get it through a chrono eventually but it would be nice to anticipate probably what it will be shooting.

Thanks

[Bols]

Others might have a better guess, I am saying around 270-275 fps. I know for sure, you are going to loose approximately 10 fps just on the 1inch difference in drawlength.

[sluedtke]

For every inch of draw length you go down you will lose 10 FPS

For every 5# draw weight you go down you will lose 10 FPS

For every 3 grains of weight your arrow is over IBO you will lose 1 FPS

For every 3 grains of weight you add to your string you will lose 1 FPS.

So I would guess about 273 on the head. It could shoot a little slower it seems like they always do.

[M77man]

Thank you for the info, we'll go with that. Not like it really matters for a hunting bow on out to no more then 40 yards right? But just wanted to know.

[sluedtke]

A heavier arrow helps out in down range shots like 30 yards and more because of kinetic energy, but it will be slower because of the weight.

[buckmaster]

heres a pretty neat little calculator.

http://www.thearcheryhut.com/calculators.php

[sluedtke]

LOL i just gave that calculator to somebody else on another thread... thats what I used for this info too.. found out the fps calc is a little bit off so rely on the words on the left and your own calculator for the fps...