The Barrett XM109, originally known as the Objective Sniper Weapon (OSW) and now called the Anti-Materiel Payload Rifle (AMPR), is a prototype semi-automatic grenade launcher. It is chambered for 25 × 59 mm grenade rounds and was developed by Barrett Firearms Manufacturing. It was designed in accordance with a requirement set out in 1994, and is capable of defeating light armor and equipment out to 2 km.