Help Please!

BossHog · 02-18-2004, 05:50 PM

Ok Here is the deal. I am trying to figure out the arrow speed of a bowtech Mighty Mite. My problem is I have a very short draw 26" set at 70lbs shooting a 400 grain finished arrow. How do I go about figuring this out if the IBO is 322fps?

PABowhntr · 02-18-2004, 06:27 PM

Start with the birth certificate for your particular bow not the IBO speed rating which is between 314 and 322 not just 322. (Don't want to mislead you).

A person loses about 10 fps for every inch of draw length below 30 inches. That would mean a 40 fps drop in arrow speed right off the bat because of your 26 inch draw length. Throw in 50 grains in arrow weight over IBO specs at 70 lbs and you are losing another 17 fps. That is a total of 57 fps. Subtract that from 314 and you get 257 fps. Subtract that from 322 and you get 265 fps.

Ofcourse that is assuming a bare bow string except for a tied-on nockset.

BossHog · 02-18-2004, 06:41 PM

Thanks PA. Does taking an additiional 10fps off sound right for typical string stuff ?
I think that 250 fps at a 400 grain shaft should give plenty of K/E any thoughts from anyone? If I only had longer arms!

Matt / PA · 02-18-2004, 07:56 PM

That sounds fine Boss Hog. No whitetail is safe!........(but I have to admit I wake up every morning and thank my gene pool for a 30" draw length!

)

PABowhntr · 02-19-2004, 05:07 AM

Quote:

Does taking an additiional 10fps off sound right for typical string stuff ?
I think that 250 fps at a 400 grain shaft should give plenty of K/E any thoughts from anyone? If I only had longer arms!

I agree with Matt. That sounds about right but it will vary depending on how much, what kind and where that string stuff is located on the bowstring. In some cases the specific speed losses could be considerably more.

Don't ask for longer arms.....most of us that have longer draws are probably too long in the draw to begin with....right Pat?

[&:]

Mike from Texas · 02-19-2004, 06:05 AM

Boss,

Send me your email and I'll send you a spread sheet that I've been building that will give you a very close idea of what speed and KE you can expect from your setup. While it is not perfect for every setup, it will at least serve as a guide. You can play around with draw weight, length, arrow weight, string accessories etc....

Based on what you said from your setup going on the low end of Bowtech's IBO speed rating (just to be conservative) it shows you to be at about 250 fps & 56# KE.

Dubbya · 02-20-2004, 12:59 AM

mike do ya think it would be possible for me to look at that spreadsheet? that sounds great.