The Alexander Arms AR-15 DIY Upper Kit (brand part no. KIT-65-16) gives builders the core parts needed to assemble a 16-inch, 6.5 Grendel AR-15 upper themselves, centered on a matte black steel barrel chambered specifically for the Grendel cartridge. The kit includes the 6.5 Grendel upper receiver, a gas block, a gas tube, roll pins, a charging handle, and a thread protector for the muzzle, giving a builder most of what’s needed short of final assembly and a bolt carrier group. Alexander Arms cuts the barrel with a 1:8 twist rate, tuned to stabilize the heavier bullet weights that make 6.5 Grendel effective at extended range from an AR-15 platform. Because this is a DIY kit, final assembly is left to the builder rather than shipping pre-assembled, making it a good fit for AR-15 owners who want to build their own 6.5 Grendel upper rather than buying a factory-complete one.

Key Specifications

• Chambered in 6.5 Grendel.
• Barrel measures 16 inches in length.
• Rifling uses a 1:8 twist rate, tuned for heavier Grendel bullet weights.
• Barrel is machined from steel and finished in matte black.
• Includes the 6.5 Grendel upper receiver.
• Comes with a gas block.
• Comes with a gas tube and roll pins.
• Includes a charging handle and a thread protector for the muzzle.
• Ships as an unassembled DIY kit, requiring final assembly by the builder.

Frequently Asked Questions

Does this kit come fully assembled? No, it’s a DIY kit, so final assembly is left to the builder.

What’s included in this kit? It includes the 6.5 Grendel upper receiver, barrel, gas block, gas tube with roll pins, charging handle, and a thread protector.

Does this kit include a bolt carrier group? The kit’s included parts cover the receiver, barrel, and gas system components; builders should confirm bolt carrier group compatibility separately.

Buy the Alexander Arms AR-15 DIY 16-inch Upper Kit, 6.5 Grendel, Matte Black

Build your own 6.5 Grendel AR-15 upper around a purpose-cut Grendel barrel. Order it through our Alexander Arms lineup of AR15 uppers, and we’ll get it ready to ship as soon as it’s available from our Lubbock, Texas gun shop.