Bees

Yep I knew that. from physics class a long time ago..

Leverdude

Everything drops at the same speed. A good BC will help a bullet retain velocity so it'll get further down range before it hits the ground but it still drops at the same rate. If both bullets have the same BC but ones heavier than the other, as long as velocity is equal they'll both hit the same. A heavier bullet, or arrow usually goes slower & hits lower as it wont get as far as a lighter, faster bullet or arrow.

The way it was explained to me is, If you were to drop a bullet at the same instant you fired one from a level barrel, they'd both hit the ground at the same instant. Just that one would be at your feet & one would be downrange somewhere.

Theres alot of variables in an arrow, fletching, design of point ect that affect how fast it slows down so it may not be as cut & dry as a bullet but I'd think the physics are very similar if not the same.

Arthur P

That's only if you fired the bullet level to the ground. You gotta take launch angle into account too.

Anybody's brain hurtin' yet? [8D]

Bigpapascout

BINGO!

Buckfevr

I know that when I went from a 5575 to a 7595 there was no need to resight. But there were a couple of reasons for that. One is that the shaft was a little thicker so the trajectory is slightly different. Second the heavier spine of the 7595's held on to a little more energy. Third I was using the same vanes on both so there was more drag on the lighter arrow.

PatapscoMike

Leverdude has the physics right, but the assumption most people are making is that the heavy and the light arrow are travelling at the same speed. When that is the case, the heavier arrow sinks less due to it's greater momentum- which causes it to be affected less by wind resistance. But if you are shooing a heavy and a light arrow from the same bow- then the lighter arrow sinks less because it starts at a greater initial speed. Try it and you will see. Switch to a lighter arrow, and your pins get closer together. This is because the arrow drops less at standard hunting distances.

Were you to shoot the arrows at a 45 degree angle, the heavier arrow would go farther than the light arrow. But that's not relevant to a hunting situation.

So, yes it's true that a heavier arrow drops less- IF IT STARTS AT THE SAME SPEED AS A LIGHT ARROW.

Bigpapascout

I do not dispute that at all

i think you gave the best explination so far Mike.

pdq 5oh

But shot from the same bow, the lighter arrow will go faster. Out to about 45 yds or so, the light arrow will drop less. Past that, the heavier arrow will retain a higher percentage of speed and drop less. I'm sure there comes a point of diminishing return, however. Slow the bow down enough, and the arrow will not go very far at all. I shot 305, and 375 gr arrows from the same bow. At 25 yds, same point of impact. At 35, the 375 gr hit about 2" lower. At 50 yds, nearly same point of impact. In a word, momentum. BTW, changing arrow weight only increases KE if the speed increases with the weight. The resulting speed loss, due to increased weight, causes the KE to be held in check.

Paul L Mohr

That doesn't work that way with my bow at all. If I shoot a 314 grn arrow at my target from 40 yards and hit the center, then shoot a 416 grn arrow and aim at the same spot it will not even hit the target. It drops more than a foot compared the lighter arrow. Small weight changes my react differently, like 25 grns or so, but when the difference is considerable heavier arrows drop more, period.

Another thing we are not taking into consideration, but Aurthur aluded to is sight paralex (sp?).
The distance your sight is above your arrow will give you the perception that your bow shoots flatter. Works the same with rifle, the higher your scope mount is it will make your rifle seem to shoot flatter out to a certian yardarge.

Use the ballistic calculator at Jacksons site to check the drop of an arrow, it does not compensate for sight height. Then try one that does, like middletons, although his tables don't work on my computer any more. I don't know if it's his site, or the Java on my computer doesn't work right. You could use a ballistics calculator for firearms if you knew the ballistic coeficient for your arrow though. At any rate I am pretty sure the one that compensates for sight height will show a flatter trajectory. I could be wrong however, it's happened at least twice before that I'm aware of.

And like everyone is saying, the key is if they travel at the same speed, which isn't going to happen out of a bow.

Paul

Wolf killer

The heavier arrow will have more kenitic energy. The heavy arrow will penetrate deeper into an animal.