Amber Tint Why Choose Bullseye for Casting? Bullseye billets can be an excellent choice for casters who are concerned about the safety issues in working with lead crystal. Bullseye billets are also significantly lighter than lead crystal and may be more economical to use. In comparing costs, remember that full lead crystal glasses weigh as much as 45% more. The specific gravity of Bullseye glass is about 2.5.