Glaser Safety Slug(R) is designed as a pre-fragmented projectile using a traditional copper jacket. Instead of a solid lead core like conventional hollowpoint ammunition"" it has a compressed core of lead shot. It's capped with a polymer ball that ensures flawless feeding and rapid follow up shots. Glaser Silver is designed for greater penetration than Glaser Blue. Glaser Silver is loaded with a compressed load of larger #6 lead shot. Glaser Silver is designed for colder climates when heavy jackets and coats are the norm.