Modern autocannons are typically not single soldier-portable or stand-alone units due to high weight and recoil; rather they are usually vehicle-mounted, aircraft-mounted, or boat-mounted, or even remote-operated as in some naval applications. As such, ammunition is typically fed from a belt to reduce reloading or for a faster rate of fire, but a magazine remains an option. Common types of ammunition, among a wide variety, include HEIAP, high-explosive dual-purpose (HEDP) and more specialised armour-piercing (AP) types, mainly composite rigid (APCR) and discarding sabot (APDS).