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 (1.2 miles).

The XM109, originally known as the Objective Sniper Weapon (OSW) and now called the Anti-Materiel Payload Rifle (AMPR), is a semi-automatic anti-materiel rifle, designed primarily for engagement of light armored vehicles and similar targets.

[1] The 25 × 59 mm round that is used in the XM109 is the same one originally developed for the cancelled XM307, product of the Objective (later Advanced) Crew Served Weapon program (OCSW / ACSW).

However, the small amount of propellant and heavy projectile resulted in unacceptably high recoil due to limiting the effects of the weapon's muzzle brake, with a recoil force of over 60 foot-pounds compared to 36 for the M107.