A 20-inch Proof Research barrel chambered in 6.5 Grendel for AR-pattern rifles. It is set up for a rifle-length gas system and a .750-inch gas block, and uses 5-groove rifling. The 6.5 Grendel pairs well with a 20-inch barrel for longer-range work out of an AR platform, and this barrel gives builders a Proof Research option for that setup.
- Brand: Proof Research
- Caliber: 6.5 Grendel
- Barrel length: 20"
- Gas system: Rifle length
- Gas block journal: .750"
- Rifling: 5-groove
