Heavier arrows have more momentum, thus they have better down range energy. Check out the thread on the Bow Hunting forum that is two pages long. Or use the search funtion on this site and type in momentum, I am sure it has been discussed here in detail.

Here is an example with the specs from my bow using the Archery Programs ballistics calculator. With a 26 inch draw and 55lbs of draw weight.

A 312 grn arrow, That is 5.6 grns/lb, I think that constitute a light arrow. This arrow would devolope 41 ft/lbs of energy at 244 fps right off the bow. At 20 yards it would be 35 ft/lbs of energy at 227 fps, and at 40 yards it drops to 31 ft/lbs at 211 fps. Those are not real great figures and typical of what a small guy or a woman would get for performance. All I can say is you better shoot em' close with a wicked broad head, no mechanicals on that set up!

Now we will figure the same bow with a heavier arrow. Lets go with a my aluminums that way 456 grns. This arrow with the same bow would have 44 ft/lbs of energy at 209 fps right out of the bow. At 20 yards it would be 39.5 ft/lbs at 197 fps, and at 40 yards it would be 35 ft/lbs at 187 fps. You give up some speed, but you can see the heavier arrows diffenitely carry more energy than the lighter ones.


Just to see what you would be losing by using the heavier arrow, I will compare the amount of drop from one to other. If you sighted the bow in at 20 yards it would be 2 inches high at 10 yards, and drop 4.5 inches at 25. Then at 30 it would be 11 iches low. Deffinately not one pin accuracy there, but I limit my shots to 25 yards(they are usally closer than 20) and use multiple pins.

Now the 312 arrow would be 1 inch high at 10 yards, 3 inches low at 25, and almost 8 inches low at 30. Not much better than the heavier arrow, you sure don't gain much in reducing judgement errors. You would still need multiple pins.


Those are actual specs from the actual bow I shoot with those exact arrows fired thru a chronograph. Not a calculator guessing what my bow would do off the IBO specs provided by the manufacturer. The only thing I used the calculator for doing the math for me.

Take it for what it is, and make up your own mind. Also note that a much faster bow with a longer draw and more draw weight my have a closer outcome between the two, but it will still fall along those lines. If you had a bow that shot real fast and could shoot with one pin out to 30 yards, a heavier arrow would still give you more momentum, but might slow the bow down to the point where you would have to use multiple pins or guess at shot placement(hold over). And if you were already getting sufficient Ke, what would be the point? That is the argument you will get from the guys shooting lighter arrows. And in that situation, it is a hard one to fight.

Did that help you out any?

Paul