# Trying to understand the power of shooting butterfly



## KawKan (May 11, 2013)

I love shooting butterfly! The increased speed results in a flatter trajectory and greater impact at the target. That much is obvious.

But I also like to understand what's going on with my slingshot, so I set up a chrony test.

I used 1632 bands set up three ways (5 inch singles, 5 inch full loops, and 10 inch singles). Each bandset was mounted on the same Dankung. Each bandset was drawn to 500 percent of the relaxed length (5-inch to 25-inch, 10-inch to 50-inch). I measured 5 shots, threw out the high and low, and averaged the remaining measurements. I also checked the resistance or draw weight of each set up.

Data with ⅜ inch steel ammo

Format Draw Velocity

5 inch singles 5 lbs 143.8 fps

5 inch loops 10 lbs 184.5 fps

10 inch singles 5 lbs 186.1 fps

The data drives three conclusions.




Velocity is a result of how much rubber you use, regardless of draw length.



Draw weight for a given percentage of elongation stays the same regardless of length.



Full butterfly performance gains are a result of adding rubber without the penalty of adding draw weight.


Note: The velocity difference between 5-inch singles and 10-inch singles is about 23 percent. The velocity difference between 5-inch loops and 10-inch singles is about 1 percent - attributable to testing error.


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## skropi (Mar 22, 2018)

Nice test. Too bad I cant shoot butterfly well yet. I did notice an extreme difference in speed with just 20cm added draw length, so I can imagine how much more powerful an added 75cm in my draw length would be. 
KawKan, do you find you are more accurate with butterfly shooting, or are you using it purely to gain power?


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## Buckskin Dave (Apr 4, 2018)

Great post kawkan. A lot of thought and planing went into that test. Were the results what you expected?


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## KawKan (May 11, 2013)

@skropi: The accuracy question is a little difficult for me. I am more accurate now, but I think it's only because I have shot longer and learned a lot, and not just because I'm shooting butterfly.

@Buckskin Dave: I was surprised with both the results of the draw weights, and the chronograph. I expected a 10 inch length of tubing to have more stretch resistance than 5 inches - but not so if they are both stretched 500 percent. Also I expected the ammo to pick up more velocity over 40 inches of acceleration (50 inch draw minus 10 inches of relaxed length) than in 20 inches (25 inch draw minus 5 inches of relaxed length). It was a pleasant surprise that the KISS principle applies to latex performance too!


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## MakoPat (Mar 12, 2018)

Thanks for sharing. That is intriguing data... and you can sling some speed! I'd need 20 more inches of arm and some extended forks.


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## flipgun (Nov 14, 2012)

MakoPat said:


> Thanks for sharing. That is intriguing data... and you can sling some speed! I'd need 20 more inches of arm and some extended forks.


Try this.






Nothing dies on the web Gary.


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## Flatband (Dec 18, 2009)

HAH! That was a while ago Paul!!! SUPERFLY SHOOTING!!!!!! Warp Drive anyone????? :rofl:


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## M.J (Nov 1, 2010)

Superfly rules!
I had a setup once that gave me an 80" draw length. It was a screamer : D
https://slingshotforum.com/topic/32489-superfly-revisited/


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## Ibojoe (Mar 13, 2016)

Good thread buddy. I've been shooting butterfly for a few years now. It seems to me the narrower the bands are at the pouch the more speed you get. Have you tried a heavy taper on any of your set ups? Also it seems thinner bands cut a little shorter shoot faster than thicker ones. I don't have a chronograph so all this is just speculation.


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## KawKan (May 11, 2013)

Thanks, @Ibojoe: I have tried some wild tapers with butterfly.

After stocking up with 5/16 steel ammo recently, I went to a 1/2-inch to 1/4-inch taper with 12 inches tie-to-tie. That light stuff gets downrange in a hurry!

I might hesitate to use a 1:2 taper with a 6-inch bandset, but it works fine with a 12-inch bandset.

I'd have to think about how to set it up, but I'm sure a chrony test comparing band tapers would be interesting.

Another chrony test could compare different thicknesses of flatbands.

Lots of questions on band performance, and each question suggests a test!


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## Tag (Jun 11, 2014)

Great post


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## Ibojoe (Mar 13, 2016)

It would certainly be interesting testing though. Especially With all the Slingshot specific elastic being produced these days it's nearly impossible to even try it all. It will really be interesting to see how far they can push it without it becoming too dangerous to shoot. I just know that when it hits the shelves I have to have it. Can't help myself!!
One has to do alot of testing anymore just to figure out a new elastics elongation factor. I love it!! Right now im trying to figure out the new Sumeike stuff. I started at 16" and have worked my way down to 11" for my 63" draw. It just keeps stretching. I've never pulled anything so easily that delivers that kind of speed. To me it's all VERY exciting!!


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## Grandpa Grumpy (Apr 21, 2013)

I wonder where pseudo tapers would fit in. I would assume a lighter draw weight than full loops but higher speed than singles.


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## KawKan (May 11, 2013)

Grandpa Grumpy said:


> I wonder where pseudo tapers would fit in. I would assume a lighter draw weight than full loops but higher speed than singles.


I'm with you on the probable results for pseudo tapers.

I'm interested in exploring tapered flats and pseudo tapered tubes, but shooting over the chrony makes me nervous. I'm always sure I'm put a ball right through the front display! LOL!

It's also a challenge to eliminate as many variables as possible, so the comparison is clear.


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## Northerner (Nov 9, 2010)

Thanks for posting! Chrono results are interesting to see and lots can be learned. I sure wish I could get comfortable with full or partial butterfly. That ball whizzing by my face never feels right but I should give it another go. Getting the same speed with half the draw weight is certainly a big motivation.


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## steveewonders (Dec 30, 2017)

Thinking about drawing a long bow to the cheek, its about the same length as a short bandset draw. Yet the draw weight of a bow is much heavier. Limbs retract at specified speed making arrows fly that velocity. At that similar draw length, arrows can fly further probably due to the higher stored energies.

Speaking of tubes, the chinese devised something that allows shooters to stuff 1632 into the core of primary tubings while leaving distal ends unaltered. Its unlike pseudo-tapering. That makes it heftier to draw, yet it seems to release heck alot faster.


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## 3danman (Mar 29, 2012)

Superfly shooting could produce some wicked speeds with thin, heavily tapered flats and light ammo. Let's get Alvaro (Luck Over Skill) a big ol' starship and see what he can do!


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## Ibojoe (Mar 13, 2016)

It's interesting that 10" of rubber (the loops and the singles) got you almost exactly the same speed only you had to pull the loops twice as hard. Keep experimenting buddy, it's awesome fun isn't it? Take care of that chronograph!!


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## KawKan (May 11, 2013)

Ibojoe said:


> It's interesting that 10" of rubber (the loops and the singles) got you almost exactly the same speed only you had to pull the loops twice as hard. Keep experimenting buddy, it's awesome fun isn't it? Take care of that chronograph!!


Those were results that surprised me.

Regarding that chronograph, it's the cheapest one I could find (Dankung) but seems to work. It just hurts a tightwad like me to spend money, I guess! LOL! And it does help answer those niggling little questions!


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