Diamondback 6.5 Grendel Barrel — 18", 1:8 Twist, Black Nitride, Mid-Length Gas, 5/8×24 Threads — Fits AR-15 Rifles (65M18M50B8R | UPC 815875019084)
Unlock the long-range potential of your AR with the Diamondback 6.5 Grendel 18" Barrel. Purpose-built for precision and real-world durability, this barrel combines an 18-inch length, 1:8 twist for stabilizing popular 6.5mm bullets, and a corrosion-resistant black nitride finish. The mid-length gas system balances reliability and recoil impulse, while the 5/8×24 threaded muzzle makes it easy to add brakes, flash hiders, and suppressor mounts. Part 65M18M50B8R delivers the accuracy, consistency, and easy maintenance that discerning builders demand—whether your target is steel at 800 yards or a pronghorn on open ground.
Why Choose This Diamondback 6.5 Grendel Barrel?
18" Sweet Spot: Extra velocity over 16" tubes without the weight of a 20". Ideal for field carry, hunting, and practical precision.
1:8 Twist: Optimized to stabilize a wide range of 6.5 Grendel bullets—from light varmint loads to 120–130gr match and hunting projectiles.
Black Nitride Inside & Out: Ferritic nitrocarburizing hardens surfaces, resists corrosion, and sheds fouling for faster, easier cleanup.
Mid-Length Gas System: Smooth cycling and a flatter recoil impulse that helps you stay on target for faster follow-up shots.
Threaded 5/8×24: Industry-standard .30-cal thread pitch for broad compatibility with brakes, comps, and suppressor mounts.
Key Features & Specs
Caliber: 6.5 Grendel
Length: 18 inches
Twist Rate: 1:8 right-hand
Finish: Black Nitride (bore & exterior)
Gas System: Mid-length
Muzzle Threads: 5/8×24
Platform Fit: AR-15 upper receivers (6.5 Grendel bolt & mags required)
Part Number: 65M18M50B8R
UPC: 815875019084
Contour/Twist Details: Specs may vary slightly by lot—request a current data sheet if you’re tuning for specific loads or suppressor use.
Performance You’ll Notice
Real Long-Range Reach: 6.5 Grendel’s high-BC bullets retain velocity and buck wind better than 5.56—perfect for practical steel and open-country hunting.
Consistent Accuracy: Quality machining and free-float setups support tight groups with match or premium hunting ammo.
Cleaner Bore, Less Downtime: Nitride treatment reduces fouling adhesion so you can return to the line faster after a few passes with solvent and patches.
Manageable Recoil: Mid-length gas plus modern muzzle devices help you spot impacts and make confident corrections.
Ideal Use Cases
Hunting: Deer, hogs, pronghorn, and predators—ethical energy and excellent terminal options from 90–130gr bullets.
Practical Precision / DMR: Confident hits from 300 to 800+ yards with good glass and dope.
Range & Steel: Flat trajectory and strong wind performance make the Grendel a blast for distance practice.
Compatibility & Build Notes
Upper/Lower: Standard AR-15 receivers; confirm handguard ID for gas block clearance.
Bolt & Magazines: Use a 6.5 Grendel-specific bolt (Type II is common) and Grendel magazines for proper feeding.
Gas/Buffer Tuning: Pair the mid-length system with an H/H2 buffer as needed; aim for a 3–4 o’clock ejection pattern.
Headspace: Always check with gauges using your chosen 6.5 Grendel bolt/BCG.
Muzzle Devices: Verify 5/8×24; re-torque and re-zero after installing brakes or suppressor mounts.
Installation Tips (Non-Instructional)
Prep & Inspect: Degrease receiver threads; lightly oil the barrel extension.
Torque & Align: Install the barrel nut to spec; verify gas tube alignment through the nut windows.
Secure Gas Block: Center the block over the port and use proper thread treatment on set screws.
Function Test: Confirm ejection and lock-back with your ammo; adjust buffer weight if needed.
Zero & Dope: Start with a 100-yd zero; record drops/wind holds for your primary loads.
Care & Maintenance
Quick Clean: Nitride bores respond well to solvent soak, patches, a light nylon/bronze brush, and a thin oil film.
Hardware Checks: Re-check gas block and muzzle device torque after the first range day.
Weatherproofing: Wipe exterior metal after rain/snow; store dry.
Pair It With
Adjustable Gas Block for suppressed/unsuppressed tuning.
Quality LPVO (2-10× / 3-15×) to exploit mid- to long-range performance.
5/8×24 Brake or Hybrid Mount to manage recoil and track impacts.
SEO-Friendly Search Terms
Diamondback 6.5 Grendel 18 inch barrel, 65M18M50B8R, 815875019084, 1:8 twist Grendel barrel, black nitride 6.5 Grendel AR-15 barrel, mid-length gas 6.5 barrel, 5/8×24 threaded 6.5 Grendel, AR-15 long range barrel, hunting barrel 6.5 Grendel, Diamondback AR barrel.
Diamondback 6.5 Grendel Barrel — 18", 1:8 Twist, Black Nitride, Mid-Length Gas, 5/8×24 (65M18M50B8R | 815875019084): the accuracy-focused, low-maintenance upgrade that brings true long-range capability to your AR-15—ready for the field, the match, and every mile in between.
The End
