sw put this idea in my head

[deadon]

He was trying to explain to me why the heaviest arrow I could shoot out of my Xbow would be more accurate at longer ranges than the lighter arrow. He said (something like) I could probably throw a tennis ball 80 MPH and I could throw a baseball 60 MPH-------- BUT--------- at 20 yrds the baseball would be going MUCH faster than the tennis ball. Some guys here at Dougs have proven this is also true with bullets .

[dougedwards]

Well, I think the most accurate answer to the question of whether the heavy projectile would proceed more accurately than a lighter one at longer distances would be like the answer to many questions which is........it depends.

Arrows are not baseballs. They are of a relatively aerodynamic structure but like any mass that is projected into the air they are affected by air density, wind, gravity and even humidity. If any two similarly sized projectiles of drastically different weights are traveling at the same speed, the heavier one will be less affected by outside forces and even harder to bring to a complete stop. This is very easy to demonstrate if you have a way to shoot the two projectiles at the same speed.

However, if you are shooting any two arrows of different weights from a crossbow which is loading up energy in the limbs which will be passed onto the arrow through propulsion, they will certainly not be traveling at the same speed when released from the bow. For the most part the difference in the rate of speed will be determined by the difference in weight (resistance) of the two arrows and also by the efficiency of the crossbow to transfer it's stored energy to the resistance provided. Some bows perform at peak efficiency when resistance is increased but there is a point of diminishing returns.

Part of the reason that a tennis ball will lose speed at longer distances is that the human arm requires more resistance than the weight of a tennis ball provides to perform at peak efficiency. So......it depends on the efficiency of the propelling vehicle to transfer energy to the projectile and also on the time that the projectile is in the air before it reaches it's destination. It also depends on what is considered "long range" as traditionally crossbow ranges have been considered to be within a 40-50 yard limit. At those ranges any 350-450 grain arrows should operate pretty accurately. But recent improvements to modern crossbow technology have stretched these self imposed limits to 100 yards and beyond.

The fun of this type of sporting activity is that we are forced to experiment with our equipment and components and record data to determine what combination provides the most preferred results. If it were not for this sometimes frustrating activity of experimentation us sportsmen would probably find something else to spend our time and money on. What else might we be doing if we were not hunting and shooting? I guess it depends.

Doug

[sw]

May 26, 2011 19:23:07 GMT -5 deadon said:

He was trying to explain to me why the heaviest arrow I could shoot out of my Xbow would be more accurate at longer ranges than the lighter arrow. He said (something like) I could probably throw a tennis ball 80 MPH and I could throw a baseball 60 MPH-------- BUT--------- at 20 yrds the baseball would be going MUCH faster than the tennis ball. Some guys here at Dougs have proven this is also true with bullets . It is only common sense but sometimes it is good to hear it said.

In all respect here to Rusty, I think a little has been lost in this translation. As Doug has alluded to, it is a combination of BC and speed primarily. Fletching effectiveness , straightness, etc, for arrows and bullet concentricity, stabilization( esp not going transonic during the flight) , etc for bullets.

[deadon]

May 27, 2011 22:07:52 GMT -5 sw said:

May 26, 2011 19:23:07 GMT -5 deadon said:

He was trying to explain to me why the heaviest arrow I could shoot out of my Xbow would be more accurate at longer ranges than the lighter arrow. He said (something like) I could probably throw a tennis ball 80 MPH and I could throw a baseball 60 MPH-------- BUT--------- at 20 yrds the baseball would be going MUCH faster than the tennis ball. Some guys here at Dougs have proven this is also true with bullets . It is only common sense but sometimes it is good to hear it said.

In all respect here to Rusty, I think a little has been lost in this translation. As Doug has alluded to, it is a combination of BC and speed primarily. Fletching effectiveness , straightness, etc, for arrows and bullet concentricity, stabilization( esp not going transonic during the flight) , etc for bullets.

Thanks Doug and sw for straightening me out, Rusty

[dougedwards]

May 28, 2011 4:09:17 GMT -5 deadon said:

May 27, 2011 22:07:52 GMT -5 sw said:

In all respect here to Rusty, I think a little has been lost in this translation. As Doug has alluded to, it is a combination of BC and speed primarily. Fletching effectiveness , straightness, etc, for arrows and bullet concentricity, stabilization( esp not going transonic during the flight) , etc for bullets.

Thanks Doug and sw for straightening me out, Rusty

Wow......I was responding to this thread very quickly as I was leaving the workplace and when I later went back to read what I had written I was thinking that this is more confusing than clarifying....LOL

However I do shoot arrows from my back deck out to 70 yards to a range in my back yard and the heavier and also longer arrows stabilize the best at longer distances. It takes nearly a full second for them to get to the target and if it is windy I notice that the lighter arrows (335 grains) are affected to a significantly greater extent than the 435 grain arrows. There is still a point of diminishing returns as a 550 grain arrow just stays in the air much too long with it's loopy trajectory and is no more accurate than the 335 grainers. Hope this practical example is more helpful than that GobbieGoop that I wrote before.

Doug

[hornet22savage]

I think I undestand what you good folks are dicussing here and can give an example related to muzzleloading. Last weekend I shot two different bullets with to different sabots but the powder charge for both was the same. I shot the Hornady 44 cal. 265 FTX and the Hornady .458 325 FTX, at 100 yds POI was that same for both bullets even though the heavier bullet was moving slower. I don't know exact speeds. Now this is at 100 yds. eventually the lighter bullet should slow down enough that tht heavier bullet would surpass it it ballistic performance. Or am I way off base here?

[deadon]

I should have told the whole story so here goes.SW had been shooting Parker Red hot arrows with the 125 gr Nap spitfire and tested it all the way out to 100 yrs. At that time IIRC he had shot his SF xbow over a thousand times. IMO he had tested and posted everything most folks would ever need to know about the Strykeforce xbow. His post was my xbow Bible. I bought a SF and loved it except the fact that I did not have the A@# to cock it By hand. Well all of a sudden to me (500 to 1000 shots later for sw ) he was shooting the Red hot arrows and the 175 gr nap spitfire. That was sacrilegious. LOL. I called him and thats when he gave me the tennis ball vs baseball analogy and it made sense to me. I was asking if the same could be true for bullets and thanks for all the input, Rusty

[hornet22savage]

I would say yes the saem apllies to bullets. Somewhere on this site it was psoted that a certain shooter was shooting 200 gr. SST bullets with 100 gr. of powder. That same person decided to try the 325 FTX with 135 gr. powder and found that the bullets ballistics were the same as the 200 gr. SST however the heavier bullet was not as affected by the wind at 300 yds. as the 200 gr. was more, energy equals more staying power. I wouls say that the same goes for arrows.

[12ptdroptine]

but then come's to play FOC..forward of center weight..and changing tip weight has an effect on the spine of the arrow..and then also the degree if any of helical on the fletching..I shoot light weight arrow from my bow..350grn's and they shoot well...flat out to 40 yds. And I can hit pretty well out to 50 yds but then trajectory come's to play.The arrow isnt carrying enough momentum..but a heavier arrow seems stable out to further distance's.But I have never shot a live animal past 21 yds with a Bow. I always thought I would be able to take a shot out to 40 pretty well...However at that range ..a puff of wind or 1 more step and a good shot could go really bad..in about 1 second. My bow isnt a slouch It puts that arrow out through the chrony at290fps... confused enough...me too...LOL drop

[dougedwards]

There is a physical law of inertia that says that any mass will not move unless some outside force moves it. Then when it does move, that same mass will continue in the same direction and at the same speed that it was initially thrusted until another force imposes upon it. It is pretty obvious that it would require more force (air density, wind, humidity, gravity) to impact a denser object traveling at a designated speed than it would to have the same impact over a less dense or lighter object (thus the baseball vs tennis ball example).

It is just that the weight of any object is not the only consideration when determining this impact of outside forces on the impetus of a moving object. Since we have an atmosphere of atoms (hydrogen, oxygen, carbon dioxide etc) this projectile is not only immediately affected by gravity as soon as it begins moving from the muzzle or arrow shelf, it is also being affected by the molecules of gases providing resistance to the projectile. At this point the shape of the mass and also it's speed come into play. Keep in mind that when any two bullets are of exactly the same shape, the weight and distribution of weight determines which one of the two is given the higher ballistic coefficient.

That's a lot of words just to say that two arrows of the same shape and weight distribution should fly exactly the same when the exact same force is being imposed upon the arrow during propulsion. But all other things being equal, the heavier thus denser arrow will be less impacted by the air than it's lighter replica. The problem is that all other things are never equal and that is where the fun begins

Doug