A Quest for the Ultimate Slingshot
by Vlastimil Zuska
Concerning slingshots I was woken from my winter sleep by a
shattering window of my flat due to an unknown slingshot shooter. I live on fifth floor,
so I remembered my boyhood beanflipper made from tire innertube and I wondered what kind
of slingshot that shooter used. To my surprise I found that there are the five slingshot
manufacturers and many considerable advanced models. So I decided, partly influenced by my
profession, to undertake a rather systematic examination of commercial products. I tested
in sequence eight store-bought slingshots (Trumark FS-1, Copperhead Desert Scout, Barnett
Black Widow, Marksman Adjustable Slingshot, Trumark FSX, Copperhead Powerstorm, Barnett
Cobra, Saunders Double Eagle) and various kinds of ammunition (glass balls 1/4", clay
balls 1/4", steel balls 3/8" and 5/16", lead balls 3/8", 11.4 cm, 9.35
mm).
The method of testing:
Shooting at distance of 10, 15 and 20 meters, from every slingshot ten firings, paper
targets of three concentric circles with diameters 10, 20 and 30 cm. After deleting the
best and the worst hits I made average results. Of course I used uniform ammo, lead balls
3/8".
Results:
At 10 meters the most accurate was Trumark FSX (with sights), next one Double Eagle,
Powerstorm and Marksman WR-3, at 15 and 20 meters Double Eagle, Barnett Cobra and
Powerstorm.
The power was measured by a number of perforated pages of wet phone book fired from 10
meters. The number one was Double Eagle, next Barnett Cobra and Powerstorm.
Conclusion:
The slingshot with single powerband is captured in an antinomy: the stronger bands, the
worse accuracy. The medium bands offer better accuracy at shorter distances, but their
effective range is small and the accuracy rapidly decreased with distance. Magnum
powerbands, due to the recoil after releasing, have worse accuracy. That result was
affirmed by a Greek group of research slingshot shooters (see www.bestguns.com). What way can lead
from that trap?
The Manufacturers in principle choose three ways: doubling bands, stabilizers and pulleys.
The Doubling (used only by Saunders for Double Eagle, which
incomprehensibly disappeared from their catalogue) of bands reduces the inner resistance
(hysteresis) of the rubber and thereby reduces pulling power and also the recoil after
releasing. That reduction results in better accuracy and more power, as Double Eagle
confirmed. Theoretically another doubling would lead to still better results and at the
end we would have a bundle of very thin rubber bands. May be an idea for producers.
Basically the same consideration probably prompted some manufacturers to develop tapered
bands (RP-2, RP-3 by Marksman, Powerstorm blue bands by Copperhead).
The way of stabilizers was chosen by Barnett (Cobra with one
stabilizer, Pro-diablo with three ones /!/) and by Trumark (FSX-2000, FS-1 XFOA),
following the same function as for bows and crossbows. Unfortunately that improvement
simultaneously debases handling and storage. The final "word" in that story
would probably resemble a porcupine.
The third way, way of pulley systems, also following the examples
of (cross)bows. Till now there is only one representative - Marksman Laserhawk Stealth.
The pulleys operate as a guide for bands, they reduce needful pulling strength, provide
additional powerband stretch and thereby increase the amount of accumulated energy and
especially eliminate after-releasing recoil or jerk by distribution of recoil into sides.
In theory the ultimate slingshot should be consist in double or
multiple bands, in pulley system and a system of stabilizers. Because the outdoor
equipments or sport and hunting market does not offer anything similar to it I had to
choose a way of my own constructions. So let me shortly describe how I arrived at the
sight of that ideal of accuracy and power. At the background of my quest was an image of
slingshot as a handy weapon, so I drop the way of stabilizers.
My first model, baptized Goliath, had double bands (Barnett yellow
ones). Pulling strength was too great and the slingshot was rather stiff apparatus. After
few firings I got a crick in triangular muscle and I had to finish temporarily my
research. Not even replacement by black Copperhead bands (for Desert Scout and Cyclone)
and finally by Trumark normal pull bands improved the situation. The model did not
overcame Double Eagle as to the combination of accuracy and power and confirmed above
mentioned antinomy of strong bands and accuracy.
The second model - Big Ben, brought into play a pulley system with
vertically situated pulleys (3.5 cm in diameter) and used Barnett bands again. Result? -
the total fiasco!
Powerband stretch was longer of 12 cm, pulling strength increased from 9 kp to 12 kp, but
the accuracy went to hell. The pulleys actually increased recoil.
The third model, named Red Hunter after my motorcycle Ariel from
1938 and according to its color, applied horizontally situated pulleys, which distribute
band recoil into sides and actually eliminate it. The power remained the same, but the
accuracy distinctly increased. However after about two hours of shooting powerband faded,
its length extended from original 17 cm to 21 cm (measured in quiescent state).
The fourth model, Black Hunter, had lowered prongs and used black
Copperhead bands. Almost a hit into the bull's eye! The accuracy was better than Trumark
FSX and even Double Eagle on longer distance, the power was comparable with Double Eagle.
For example I hitted a chimney of a hunter cabin three times from five shots at the
distance of 30 meters. The chimney had a diameter of 10 cm and after my sixth shot
collapsed.
The fifth model, Black Gulo (wolverine in Latin) used large
polyamide pulleys and prong extension. With Barnett yellow bands the result was similar to
the Red Hunter, the same power, but better accuracy. I also tested Marksman RP-2 bands:
the accuracy at shorter distance was very good, but the power rather weak. Certainly it is
not by chance that Marksman has produced for their Stealth stronger bands RP-3, moreover
tapered ones. Unfortunately at present RP-3 is not on Czech market.
The sixth model, Black Window, was based on discovery that holding
parallel to the ground, i.e. horizontally improves accuracy (that way of holding is
recommended by Trumark and Saunders). Because personally I do not like that kind of
holding, I decides to construct a mixed model with prong of vertically held slingshot and
with a handle for horizontal holding. Naturally I used a pulley system. For additional
increasing of accuracy I applied a windowlike prong. With the use of Trumark heavy pull
bands I arrived at a combination of power and accuracy which overcomes Double Eagle.
In future I prepare examinations of RP-3 on the Black Gulo and the
Black Window and Double Eagle bands on Black Bear (Alas, also Double Eagle replacement
bands disappeared from Saunder's catalogue). Oh, I have not mentioned my seventh model.
Just mentioned Black Bear has double bands and double pulley system, i.e. four pulleys in
all (I tried Barnett's and Trumark normal pull). The slingshot is very strong, but the
pulling strength still too great and the accuracy a bit worse than Big Gulo's. Probably by
using two RP-2 I would obtain very effective "toy", still pretty heavy.
So I hope that I have not bored my fellows slingshot shooters and
that we together would come to the Dark Tower of the ultimate slingshot.
Vlastimil Zuska
Kodanska 65
101 00 Praha 10
Czech Republic
EUROPE
e-mail: vlastimil.zuska@ff.cuni.cz