We may earn revenue from the products available on this page and participate in affiliate programs. Learn More ›
I shot 80 arrows over a Garmin C1 chronograph, from point blank out to 50 yards, to find out how various factors, including arrow weight, draw weight, draw length, fletching, and tuning, affect arrow speed. Then I found how much a 10 fps and 20 fps increase in speed changes your trajectory from 20 to 50 yards. Here’s what I learned.
Tune Matters
The difference between a slight right tear through paper and a bullet hole was 0.5 fps at point blank and 1 fps at 50 yards. That’s not a huge increase in speed, but what was interesting was how much more consistent the speeds were once the bow was tuned. There was a 2 fps extreme spread with the untuned bow and a 0.08 fps extreme spread with the tuned bow.
Chrono Readings with a Slight Right Tear 271.6 (2 fps ES)
Chrono Readings Tuned 272.1 (.08 fps ES)
Arrow Weight
I used three arrows for this test: an Easton Sonic 6.0 that weighs 440 grains, an Easton 5.0 that weighs 445.8 grains, and an Easton Axis Long Range 4mm that weighs 475.6 grains. All shot a bullet hole through paper and were fletched identically.
Chrono Results
- Easton Sonic 6.0: 274.3 fps
- Easton 5.0: 272.2 fps
- Easton Axis Long Range 4mm: 264.1 fps
The 6-grain increase in arrow weight dropped speed by 2 fps, and adding 35.6 grains decreased speed by 10 fps. That’s about 1 fps lost for every 3 grains added.
To see how arrow weight affects down-range arrow speed, I shot these same arrows over the chronograph at 50 yards. The Sonic and 5.0 shot pretty much the same arrow speed at 50 yards. And the heavy arrow was only going 4.6 fps slower than the lighter arrows. So it went from a 10 fps difference at point blank to just a 5 fps difference at 50 yards.
50 Yard Chronograph Readings
- Easton Sonic: 249.4 fps
- Easton 5.0: 249.3 fps
- Easton 4mm Axis: 244.8 fps
Fletching
I tested two different fletching configurations at 50 yards. A four-fletch 2.25 TAC Driver and a three-fletch Blazer. The four fletch shot about the same as the 2.75 TAC Driver with just a .5 fps gain in speed. The Blazer shot about 3.5 fps slower at 50 yards.
Fletching 50 Yards
- Four Fletch 2.25 Tac Driver on an Easton Sonic 6.0: 249.9 fps (2.75 TAC Driver Speed: 249.4 fps)
- Three Fletch Blazer on an Axis 4mm: 241.4 fps (2.75 TAC Driver Speed: 244.8 fps)
Draw Weight
I set up the test bow at the middle limb position, which is about 5 pounds off the max. That’s the farthest I could drop the draw weight while keeping the arrows in tune.
To see how much draw weight affects arrow speed. I gave the limb bolts one turn at a time and shot through the chronograph until I hit the max. The first turn in raised the draw weight 1.6 pounds and I got a 3.7 fps increase in speed. The next turn increased draw weight 2.2 pounds and jumped speed up 5.2 fps. That’s a total of an 8.7 fps increase and 3.8 pounds from the starting point. The bow needed a half turn to hit the max draw weight, which jumped up the weight by about another pound. Speed increased by 3 fps in that final pound. In total, I increased draw weight by 4.9 pounds and speed by 11.5 fps.
On average, I got 2.25 fps gained for every pound of draw weight. The exception being the last turn of draw weight, which gained 3 fps for the pound increase.
Draw Length
Next, I wanted to see how much an inch of draw length changed speed. I did this test at the far end of the adjustment range and the middle of the adjustment range on a rotating module. At the far end, I got 8.8 fps difference, and in the middle of the mod, it was 10.3 fps difference for an inch adjustment. I also tried .5 inch increments and saw 3-4 fps difference.
Does Speed Matter?
Now that I know what affects speed and how much, the remaining question is: Does any of it matter?
I compared the trajectory of the Easton Axis 4mm Long Range (264 fps) and Easton 5.0 (273 fps) at 55 pounds and the Easton 5.0 at 60 pounds (283 fps) from 20 and 50 yards. I started by sighting in at 20 and shooting a group. Then I went back to 50 yards and aimed at the same point with the same sight setting. This shows the distance between the 20 and 50 yard impact point. The arrow traveling 264 fps dropped 35 inches, the 273 fps dropped 30 inches, and the 282 fps arrow dropped 26 inches. So the arrows were dropping an additional 5 inches between 20 and 50 yards per 10 fps decrease in arrow speed.
Read Next: Best Hunting Arrows
Final Thoughts
Arrow speed can provide a noticeably flatter trajectory once you get about a 10 fps or more increase in speed. If that’s something that appeals to you, the best way to get there is to drop some arrow weight and increase draw weight. Once bow season is over, you can add a turn or half turn to your limb bolts every month or two — while continuing to practice regularly — and you’ll easily add an extra five pounds to your draw weight. For arrow weight, you can look at some of the low-GPI arrows available, like the Easton 5.0.
Read the full article here
