Buy HSM Cowboy Action Ammunition 41 Remington Magnum 210 Grain Hard Cast Lead Semi-Wadcutter Box of 50. HSM has become known as one of the top ammunition manufacturers in the country. HSM utilizes the highest quality components to offer extremely consistent, accurate, and high performing ammunition to shooters, hunters, and law enforcement. The Cowboy Action line of ammunition is suitable for Single Action Shooting or hunters who want a more traditional option for the field. The moderate recoil and excellent accuracy of this ammunition will satisfy all shooters regardless of application. This ammunition is new production, non-corrosive, in boxer primed, reloadable brass cases.