Some of you guys have quoted KE for my set up when using carbons. I have been trying to use the charts on Jackson's site to get KE for a little different set up but evidently I'm not smart enough.<img src=icon_smile_blush.gif border=0 align=middle> I am shooting a Parker feather mag II at 61 lbs.-27" draw length-Muzzy zero effect rest-string loop-kisser button and two cat whiskers(small)I'm shooting some 2117 logs at 28" that weight 520 grains. They shoot much better than the Easton epics I have been shooting. I have been able to tune both arrows to a perfect bullet hole thru paper at 5 feet so I know my tune is good. I don't have any left or right with either arrow but the carbon seem to string up and down. The 2117 shot tight groups and unlike the carbons, I was able to shoot 3 different style broad heads to the same point as my field points. The carbons were eractic at best with any head except a mechanical. I don't have enough KE to shoot the carbons with mechanicals. Can anyone tell me the KE with the 2117 out of my bow. I would greatly appricate it.
DoninVa, to give you an exact number for your KE, you would have to shoot an arrow through a chronograph. I can tell you this, your KE will change very little regardless of what arrow you should. The KE should go up slightly with a heavier arrow, but not much.
If you get to shoot through a chrono, here is the formula to figure out KE.
velocity(in fps)X velocity X arrow weight(in grains)
divided by
450240
I just ran your setup through 'The Archery Program' and show you are right around 208 f/s with 50.5 ft/lbs of KE with the 2117 weighing 520 grains.
I agree that this isn't enough KE for mechanicals and really respect your decision to use the heavier arrow for accuaracy purposes rather than speed.
Big Country hit a home run with his advice regarding your KE not changing much. Not many people grasp this concept and will mislead you into thinking by changing arrow weight your KE will change drastically......it just don't!
Shoot it accurately and you will have no problem with the harvest this year.
Help with KE please
