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Main Boards => PowWow => Topic started by: Bob B. on October 10, 2011, 02:49:00 PM

Title: Draw length question??
Post by: Bob B. on October 10, 2011, 02:49:00 PM
I have been curious lately and figured I would ask those in the know ... if 2 identical bows - at identical poundages - with identical arrows -  were shot at 2 different draw lengths, 28 inches and 30 inches, would they ( in theory ) shoot the same?

Example, two 64 inch R/D bows at 50 pounds, with correctly  spined 500 grain arrows, one being drawn to 28 inches @ 50 pounds, the other drawn to 30 inches at 50 pounds.  Would they again, in theory, shoot the same?

I often wonder this just because I often hear about the "longer power stroke" of the longer draw give a bow better cast.  I also hear "pounds are pounds" - energy imparted or transfered to the arrow is all that matters and the amount or time the arrow is on the string is of little consequence.

So, does draw length matter if the full draw weight is equal?

Bob.
Title: Re: Draw length question??
Post by: tg2nd on October 10, 2011, 02:53:00 PM
Yes it does. If I remember right O.L. said 1" more drawlength equals 2-3# of drawweight.
Title: Re: Draw length question??
Post by: bryan r on October 10, 2011, 02:57:00 PM
50@28 and 50@30? I imagine that the longer power stroke would equal more energy being transferred to the arrow.
Title: Re: Draw length question??
Post by: Jeff Strubberg on October 10, 2011, 03:01:00 PM
The longer you keep pushing the arrow, the closer it will come to the bow's "terminal velocity".

A short power stroke is the reason crossbows have such lousy power/draw weight ratios and why you see 150# crossbows.
Title: Re: Draw length question??
Post by: wingnut on October 10, 2011, 03:18:00 PM
Depending on the bow used you should see about 4 fps added for each inch of drawlength added.

So the 30" will be about 8 fps faster then the 28".

Mike
Title: Re: Draw length question??
Post by: Night Wing on October 10, 2011, 03:24:00 PM
What "they all" said above.    :thumbsup:
Title: Re: Draw length question??
Post by: Bob B. on October 11, 2011, 08:11:00 AM
Thanks for the info guys, I appreciate it!

Bob.
Title: Re: Draw length question??
Post by: dragonheart on October 11, 2011, 08:16:00 AM
The arrow changes.  It is longer at 30" and requires more spine than the 28" arrow.  That is one of the major variables.