PVC vs ABS
PVC (Polyvinyl Chloride) - Most common spudgun construction material. Gets brittle in cold weather, and may shatter if dropped or abused. Pressure rated PVC is easy to find in the U.S., although large diameter pipe is difficult to find. PVC is illegal for compressed gas applications.
ABS (Acrylonitrile Butadiene Styrene) - A plastic used in plumbing applications. More resistant to shock, low temperature, and chemicals, but difficult to find rated for pressure. Pressure rated ABS is legal for compressed gas applications.