Thread: Speed for Arrows

Another factor is GPI (grains per inch) of your arrow.

People often cite light weight as a benefit of carbon arrows, but if you look at the top flight carbon arrows they will have a smaller outer diameter yet higher GPI when compared to cheaper carbon shafts.

What you want is a high GPI in a small diameter, which cuts wind drift significantly yet delivers/retains more energy on impact.

Cutting the arrow as short as possible and using an overdraw on a compound bow is done for a few reasons:

1- Stiffen the arrow shaft, a shorter shaft is stiffer, so if you can get away with a slightly lighter spine arrow cut short you are going to get better velocities (on a tuning front, it is impossible to have too stiff of an arrow shaft on a compound, too heavy? - yes too stiff? no!)

2- Effectively shortens your brace height- think about the distance the arrow has to travel between the end point of the powerstroke of the cams (where the string is at rest) and the arrow rest. Reducing this distance has a similar effect to a firearm with a shorter locktime, but in the case of bows you get a little more speed as well.

However, do all of the above with a shit ton of caution. If you shoot your wrist or blow up an arrow into your bow arm it's your own fault.

Yet some people fixate on how many grains they can stick on the end of an arrow... Seen better trajectory at a caber toss!