Iwas correct as listed the loss of trajectory of the arrow with the target being 40 yards awayusing ones 20 yard pin as a aiming reference. I am not listing the "drop" as you implied. I know the difference.[/align]

Here is a breakdown for 320 FPS......

yards velocity trajectory k/e
0320.00,-4.60, 75.01,
1 319.56,-4.04, 74.80,
2319.12,-3.52, 74.59,
3 318.68,-3.03, 74.39,
4 318.25,-2.57, 74.19,
5 317.81,-2.15, 73.98,
6317.37,-1.76, 73.78,
7 316.94,-1.41, 73.58,
8 316.50,-1.09,73.37,
9316.07,-0.80,73.17,
10315.63,-0.55,72.97,
11 315.20,-0.34,72.77,
12 314.77,-0.16,72.57,
13 314.34,-0.02,72.37,
14 313.90, 0.09, 72.17,
15 313.47,0.17, 71.98,
16 313.04,0.20,71.78,
17 312.61, 0.21,71.58,
18 312.18, 0.17,71.39,
19 311.75, 0.10,71.19,
20 311.33, 0.00,70.99,
21 310.90,-0.14,70.80,
22310.47,-0.32,70.61,
23310.05,-0.53,70.41,
24309.62,-0.7870.22,
25309.19,-1.06,70.03,
26308.77,-1.38,69.83,
27308.35,-1.74,69.64,
28307.92,-2.14,69.45,
29307.50,-2.57,69.26,
30 307.08,-3.03,69.07,
31306.66,-3.54,68.88,
32306.24,-4.08,68.69,
33 305.81,-4.66,68.50,
34 305.40,-5.27,68.32,
35 304.98,-5.93,68.13,
36 304.56,-6.62,67.94,
37 304.14,-7.35,67.75,
38 303.72,-8.11,67.57,
39 303.30,-8.91,67.38,
40 302.89,-9.76,67.20,
41 302.47,-10.63,67.01,
42 302.06,-11.55, 66.83,
43 301.64,-12.51, 66.65,
44 301.23,-13.50, 66.46,
45 300.81,-14.53, 66.28,
46 300.40,-15.60, 66.10,
47 299.99,-16.71, 65.92,
48 299.58,-17.86, 65.74,
49 299.17,-19.04, 65.56,
50 298.75,-20.27, 65.38,
51 298.34,-21.53, 65.20,
52 297.93,-22.83, 65.02,
53 297.53,-24.18, 64.84,
54 297.12,-25.56, 64.66,
55 296.71,-26.98, 64.48,
[/align]

Matt

Your 284 FPS setup would lose -4.63 inches of trajectory from 40-45 yards.

Your 306 FPS setup would lose -3.90 inches of trajectory from 40 - 45 yards.

So Basicaly you make up 3/4 of an inch with the extra 22 FPS.

It would for sure help you stay in the 10 ring on some of the larger McKenzie targets and god forbid the 8's of the smaller ones

For all those interested, I think pinwheel softwaremay still have the free 10 period to try it out. You can run the yardage errors simulation on the second page of target simulations.

Holly S#!+ Batman...I'm surrounded by geniuses! Sorry couldn’t resist

All of what you all just said is exactly why my next bow is the one that will shoot 280fps @ 60# with a smooth draw!

Check out my signature!

edit: Will post pics when it comes in!

buckeyebuckhntr, my mistake. I just assumed you were talking about plain arrow drop because anything else would be so far out of the ball park...

Here's what you said that is incorrect:

As you can see from the trajectory calculator's figures on Matt's situation, his 40 yardmidrange trajectory flattened barely a full inch and his point of impact only changed .7" or sofor his extra 22 fps!

In the real world, unless he changed fletching to a smaller size with less drag, the actual gain would be even less, because drag for subsonic projectiles increases by the cube of speed. Speed up the arrow, it encounters more drag and slows down quicker.

If you doubt that, try this little experiment next time you're driving down the highway. 22 fps is roughly 15 miles per hour. Set the speedometer on55 mph and stick your hand out the window. Now pull it in and speed up to 70 mph. Stick your hand out the window again. Compare the amount of wind resistance you felt at each speed.

Speed only increased some 21% but you can tell that wind resistance on your hand is a heckuvalot greater than that! Speed up the arrow and it encounters the same drag effect. Fortunately,the arrow'sfrontal area is much less than your hand, and it obviously has a more aerodynamic shape,sothe effect isnot quite as dramatic. Still quite apparentthough.

Matts Trajectory picked up that .73 inches over 5 yards though. Not to bad IMO the22 FPS helps him stay in the 10 ring on a misjudged distance shooting for 40 yards on a 45 yard shot.

I researched (trajectory in relation to FPS) because I was tired of hearing my short draw length friends cry about dropping points from misjudging yards. No more excuses for them now

True, assuming he held stead fast 4.63 inches into the 10 ring at 6:00 at a 45 yard target and shooting it for 40 yards. But in the hunting industry that 90% of these archers are these speed chases are irrelavant.

Don't get me wrong, I love a fast bow too but too many archers give up adequate arrow weight chasing speed not to mention ability to shoot said set up. Unless you can take nocks off an arrow every time at 45 yards, human error comes into play and with pin gap remaining the same at certain speeds, hunters are better off shooting a heavier arrow at nominal weights and still getting plenty of speed/KE....

Great topic and conversation. I want both and I think I'm very close. 296 fps from a 405 grain300 spine arrow!BAM! Ohhhh wait, I think I hear something... it sounds like80 ft pounds of KE coming my way. Stick!

ive always been a firm beleiver, that speed is a benifit if it can be controled. a lot of archers do get a advantage from speed, but loose the advantage with not being able to control it!(but like everything else its just a opinion)

Well, you guys can hash out the physics of this thing, cause I fear this is over my head. ButI know one thing without question......Let's say I shoot a target for 35 yards and it is 40. My old Bear Whitetail would shoot plumb under the deer, not even touching it. Now, my new UltraTec would put a kill shot on it, no question. One thing is obvious......speed is a contributing factor to better shooting. I also agree, though, that too fast contributes to poor shooting.