For someone who enjoys reloading and wants high quality, the Lee Shotgun Slug Mould (Includes Handles) is hard to beat. Because of its affordability, this mould saves money over buying ammunition. Aluminum is used by Lee to create mould blocks, making them rust resistant. Aluminum also heats up and cools down fast, especially when compared to iron and steel moulds.In addition, aluminum is a light material, so the risk of fatigue on the bullet caster is less. Lee CNC machines the block halves in an effort to produce rounder and more correct sized bullets, even in just a few casts.