arrow speed vs. poundage

I have been shooting a Z7 Mathews 27" draw with a string loop. Shot some arrows through the chronograph at 70 and 62 pounds.

acc340 412 grains 70 269 fps 66.22 energy 62 255 fps 59.5
max 350 375 grains 70 282 fps 66.23 energy 62 266 fps 58.93
fmj 433 grains 70 263 fps 66.52 energy 62 249 fps 59.63
alum.2413 461 grains 70 256 fps 67.1 energy 62 242 fps 59.96
alum 2117 512 grains only shot at 62 231 fps energy 60.68
I originally shot this bow when I got it at 64 lbs. and when I put a new string on it with the limbs tight was 70 lbs. I took 3 turns out of the limb screws and shot it with out knowing the poundage and wrote the speeds down before rechecking the draw weight to find out it was 62 pounds. The last number after the fps in the 62 pound is the energy number.
The numbers for what I wrote are type of arrow, next is weight. 70 is for 70 pounds, the next number is the feet per second, followed by knetic energy. then 62 is 62 pounds pull weight , followed by the feet per second and followed by the energy. This is what I came up with and thought I would pass along. ce61

If I'm looking at it correctly, the 70# draw weight resulted in 66 +/- ft-pounds of energy.

The 62# draw weight resulted in 59+/- ft pounds.

So, 8 pounds of draw weight was good for about 7 ft-lbs of energy.

Yes about 15 fps and 7 ft. lbs. energy. The difference in pulling the bow was a lot. At first, after taking the 3 turns out, my bow pulled so easy, I thought I had gone below 60 lbs. then shot it through the chronograph and couldn't believe how much speed I didn't lose. Thought this was interesting and would pass this along. ce61

Yep. My bow's maximum is 60 but it tuned better at 58. When I shot a friend's set at 70, it was a big difference.

For an eastern treestand whitetail hunter, if you've been in the stand a long time on a cold morning, that 58 feels like 70 and I'm sure that 70 feels like 80!