arrow kenetic energy question

[thomas74p]

When calculating the KE of the arrow folks take the grains and the fps and come up with a number. My question is: are they taking the speed at the recommended 5 ft from the chrono OR are they taking the speed measured at a longerdistance say 15 or 20 yards where the arrow will actually be impacting the animal?

[half eye]

It would depend on the shooter, I suppose. But having said that, kinetic energy calculations are derived by calculating mass weight times velocity squared....an arrow will never look good on a KE chart......luckily that is not how arrows (or rather the broadhead) kill. They kill by penetration of the thoracic cavity (or other vital organ such as liver) and exanguation. The KE is valuable for consideration of hydrolic shock and the energy required for that process.

A good example is looking at body armor....a panel rated to stop 44 mag and 9mm SMG... will not stop an ice pick + 1 pound dropped from 3 feet down a tube. ( both are/were NIJ test standards)

But like I said, the distance to the Chronograph is up to the shooter.
rich

[Stringman]

Also, most folks willing to part with the cash to purchase said chrono are reluctant to shoot at it from 20 yds.

[thomas74p]

Also, most folks willing to part with the cash to purchase said chrono are reluctant to shoot at it from 20 yds.

didn't think about that. That's funny.
Guess that answered that.

[Pat B]

If I can hit my target at hunting range and my arrow is over 500gr, even at 130 fps it can be a kill shot. With good arrow flight and a sharp broadhead the weak link is the nut behind the string.     Numbers don't make kill shots, the archer does.

[coxral]

If I can hit my target at hunting range and my arrow is over 500gr, even at 130 fps it can be a kill shot. With good arrow flight and a sharp broadhead the weak link is the nut behind the string.     Numbers don't make kill shots, the archer does.

100% agreed! Sharp BH & good shot=Dead critter!

[bowandarrow473]

If you hit it anywhere in the lung or heart area with a nice and sharp broadhead coming out of a bow over 35 pounds and with an arrow of decent weight.  That deer is going down and won't be back up for awhile.