Yes they are made out of PC, a type of plastic I believe (someone please correct me if I'm wrong). They go through a molding machine that injects heated PC into the molds, hence air is injected into the mold at the same time. Shame I couldn't just make them from freezer.Looks like they just popped out of the freezer. Are they plastic with air bubbles?
Thanks for the information! Lots of Chinese models are made in PC these days. They are almost unbreakable under normal circumstances, and on top of that, they are really affordable.Nice slingshots you have there...very futuristic looking!
Here is some relevant reading about PC (Polycarbonate) at Wiki:
(Quote) "Polycarbonates (PC) are a group of thermoplastic polymers containing carbonate groups in their chemical structures. Polycarbonates used in engineering are strong, tough materials, and some grades are optically transparent. They are easily worked, molded, and thermoformed.
"Polycarbonate is a durable material. Although it has high impact-resistance, it has low scratch-resistance. Therefore, a hard coating is applied to polycarbonate eyewear lenses and polycarbonate exterior automotive components. The characteristics of polycarbonate compare to those of polymethyl methacrylate (PMMA, acrylic), but polycarbonate is stronger and will hold up longer to extreme temperature. Polycarbonate is highly transparentto visible light, with better light transmission than many kinds of glass.
Polycarbonate has a glass transition temperature of about 147 °C (297 °F; 420 K), so it softens gradually above this point and flows above about 155 °C (311 °F; 428 K). Tools must be held at high temperatures, generally above 80 °C (176 °F; 353 K) to make strain-free and stress-free products. Low molecular mass grades are easier to mold than higher grades, but their strength is lower as a result. The toughest grades have the highest molecular mass, but are much more difficult to process.
Unlike most thermoplastics, polycarbonate can undergo large plastic deformations without cracking or breaking. As a result, it can be processed and formed at room temperature using sheet metal techniques, such as bending on a brake. Even for sharp angle bends with a tight radius, heating may not be necessary."
In other words, sounds like excellent slingshot making material...perfect!