Barrett XM500

The Barrett XM500 was developed as a prototype .50 BMG anti-materiel rifle using a bullpup layout. Its concept was straightforward: retain the long-range materiel effect associated with Barrett heavy rifles while reducing overall length. That made it potentially attractive for vehicle crews, airborne forces, and special operations users who needed a powerful rifle but had limited space.

The XM500 used a semi-automatic, gas-operated concept with the magazine behind the trigger. A bullpup .50 caliber rifle can be shorter than a conventional layout without sacrificing barrel length, but it also changes balance, reloading ergonomics, and shooter interface. The design illustrates why compactness alone does not guarantee adoption in precision or anti-materiel weapons.

The XM500's value in a database is analytical rather than operational. It shows the pressure to make heavy anti-materiel rifles more portable, while also showing the difficulty of moving a prototype into widespread service. Users comparing Barrett rifles should view the XM500 alongside the M82/M107 lineage and the later experimental XM109 payload rifle.