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Main Boards => PowWow => Topic started by: Traditional-Archer on February 19, 2010, 03:03:00 PM

Title: Speed Brain
Post by: Traditional-Archer on February 19, 2010, 03:03:00 PM
I was reading this article today.
Not that it makes a difference to me, but how much drop does an arrow have from 30 yards going from 180 FPS to 305 FPS.

I am not a math genius so I will leave this one to the pro's. My guess would be maybe 2 to 3 inches at 30 yards what do you think. Can someone figure this out? I am a mixed up don't give a hoot.

Why do some people get hung up on speed, a Lion is much slower than a Cheetah is the Lion less a predator. I can't out run a Cheetah or a Lion, but most likely I can out run you. Am I less a snack than you? My wife might not be as pretty, I better not go there.   :knothead:  

What you got for me, let me know what speed has to do with completion.    
 
QuoteAnother reason why the recurve is strictly a short-range bow is the relative slowness that an arrow propelled travels. For example, McDaniel said that his Martin Hatfield Take Down, which has a draw weight of 60 pounds, will send forth an arrow at 180 feet per second. Conversely, arrows coming from his compound will reach 305 feet per second. At a distance of 30 yards, the arrows coming from a recurve are rapidly losing speed, as well as dropping.
 
:biglaugh:
Title: Re: Speed Brain
Post by: Chris Shelton on February 19, 2010, 03:10:00 PM
who cares how fast they are going, or how much they slow down, how much momentum and energy do they loose!  Who is that quack?
Title: Re: Speed Brain
Post by: brill16hockey on February 19, 2010, 03:19:00 PM
Dead is dead, no matter how fast the arrow got there.
Title: Re: Speed Brain
Post by: Earthdog on February 19, 2010, 03:20:00 PM
I have fast,slow and in between,the only thing that effects anything I do with any of them,,is me,,,,I can really mess it up at times :)
Title: Re: Speed Brain
Post by: Hud on February 19, 2010, 03:24:00 PM
In order to answer your question, you would need to set a mechanical release, and probably a laser to measure the drop. Arrow weight, size of feathers, and diameter of shaft, would affect the flight and drop.

Personally, it is not something I have tried to figure out, shooting instinctive. But I think it is a lot more than a couple inches at 30 yds.

Although the compound is faster, I doubt it will shoot a heavy arrow any better than a good recurve or longbow. The heavier arrow is going to penetrate better than a light weight arrow. Bows with longer limbs are generally more efficient than short limbs in a recurve or longbow.  

There too many variables in play to answer your question.
Title: Re: Speed Brain
Post by: Encino Man on February 19, 2010, 03:37:00 PM
Outside of not knowing the coefficency of the arrow. A general calculation from a ballistic calculator derived 48" @ 30 yards using 180 fps and about 18" for the same arrow at 300 fps with a 520 grain arrow.

But then again...Who the heck cares.
Title: Re: Speed Brain
Post by: COLongbow on February 19, 2010, 03:44:00 PM
In order to give some input, I have to admit that I watch some of the bowhunting shows on TV. Many times guys shooting ultrafast compounds with light arrows exhibit shallow penetration on deer, while trad guys shooting relatively slow, but heavy, arrows report routine complete pass-throughs. I think accuracy and a sharp broadhead are the important criteria. If I was hung up on speed I wouldn't be shooting a longbow.
Title: Re: Speed Brain
Post by: Jeff Strubberg on February 19, 2010, 03:54:00 PM
Mmm, there is an answer to this in Roy Marlow's book.  He has charts of drop rates for fixed-weight arrows.


Even so, the authors statements are shallow and, pardon the pun, off target.  The question isn't whether the recurve is slower than the compound...that's obvious.  The question is does the recurve have the power to kill efficiently at 40 yards.  Just as obviously, the answer is yes, providing the archer does his part.

Your author sounds like someone hawking a product to me.
Title: Re: Speed Brain
Post by: HATCHCHASER on February 19, 2010, 04:08:00 PM
I like fast for efficiency.  It means I can shoot a heavier arrow with the same trajectory. I don't look at fps I look at momentum. Ymmv.
Title: Re: Speed Brain
Post by: on February 19, 2010, 04:15:00 PM
My past experiences with target set ups with Bear takedowns tells me that the variations from one set of limbs to a heavier and faster set of limbs shooting the same arrow are not enough to make very much difference at all with ten pounds of weight jumps for where the pin would be placed on the target, an inch at twenty yards.  With the average recurve or longbow it is not even anything to consider with reasonable arrows.  Extremely heavy arrows will change the effective drop more, but even that is just one of those things that one learns to deal with through practice.
Title: Re: Speed Brain
Post by: Ragnarok Forge on February 19, 2010, 04:51:00 PM
Actually there are two ways to find the answer to the original question.  One is to shoot a compound bow shooting 305 fps from a hooter shooter and then a recurve or longbow shooting at 185 from the exact same position.  Then measure the difference between the two arrow impact points.  Fletchings, shaft diameter, etc... tend to show a lot more effect on speed out past 30 yards.  Closer in it shows a lot less.

The other would be to break out a physics book or balistics calculator and run the numbers. for impact point with the bows set at 0 elevation.  i.e. level.  

Another correlation that will get you close is half the speed = twice the drop.  Not science but it should be close.  You still have to figure out the drop for the faster arrow.