A user configurable and maintainable firearm sound suppressor is provided. The sound suppressor is a magnum powered rifle suppressor that can be configured to provide suitable use on a high-powered rifle or a pistol. A mount interface of the suppressor can be replaced and a dual taper baffle can be removed and replaced with a pistol recoil booster system which allows optimal use for both rifles and pistols. The dual taper baffle and rifle or magnum mounting interface adds safety factor such that system durability and safety are not compromised. The user configurable and maintainable firearm suppressor allows the end user to have ideal firearm handling characteristics for a wide variety of firearms, reducing the need to purchase numerous sound suppressors for a collection of firearms. A novel two-part end cap allows disassembly of the suppressor and prevents inadvertent loosening of component parts during use.