Or even worse, the difference between 65 yards and 68 yards is a wounded animal. I would FAR rather have a clean miss than a p*#@ poor hit!

I thought about this a little bit, and ran some real world numbers against the chart. The program's chart shows the trajectory of the 447 grain Axis FMJ, starting out level andgoing 257 fps as follows:

0 yds -0-
10 yds -3
20 yds -11
30 yds -25
40 yds -44
50 yds -72
60 yds -104
70 yds -145

But the arrow is zeroed at 20 yards, and the line of sight is about four inches above the arrow - forcing the arrow's trajectory to start out uphill to cross the line of sight at 20 yards. The distance from the peep to the pins, at full draw, is 26.25". I measured the center to center of the pin spacing on the sight, which is zeroed for this arrow,and calculated the real world arrow drop based on triangulation:

20 yds -0-
30 yds -6.7
40 yds -17.4
50 yds -35.3
60 yds -61.9
70 yds -93.3

This looks more like what an arrow would actually drop if you tried to shoot all these distances with your 20 yard pin in the field. You would be about three feet low at 50 yards. I do think you could use the chart to predict, for instance, that a 267 fps arrow would drop 2.5" less at 50 yards than a 257 fps arrow - once you corrected each arrow's trajectory so they both are zeroed at 20 yards.

If you had a bow that shot 260 fps and had a 20, 30, 40 and 50 yard pin I doubt you would even have to change any of them if you increased to 270 fps. The only difference you would see would be on a chronograph.

Paul

My Airborne actually produces more KE with a 400 gr arrow than it does with a 500 grain arrow.

That's what my scales, chrono, and a little math tell.

I'd give up a little KE if I had to for the extra speed in my setup anyway, but those figures did surprise me.

Dan

Those numbers are interesting. But when considering that KE is a function of the velocity squared, and since a lighter arrow will have a greater velocity, not all that surprising. I would be interested in comparing their respective momenta!

I thought they were rather interesting myself. I had never saw that out of one of bows before. When I dropped down to 340 grain arrow the KE went down a bit as expected, but the bow really seem to like the 400 grain CX Aramid so that's what I'll feed it. 60# bow at 28" draw pumping out over 70# of KE.

Dan

I would feed it the same thing as well! Actually I saw an obscure bit of data in work done by Dr. Ashbywhich indicated that a 400 grain arrows was a great performer.....