HS-6 is a fine spherical propellant that has wide application in pistol and shotshell. HS-6 is a fine spherical propellant that has wide application in pistol and shotshell. In shotshell, HS-6 yields excellent heavy field loadings in 28-, 20-, 12- and 10-gauge. HS-6 is truly an outstanding spherical propellant and identical to Winchester's discontinued 540.