Diamondback DB Barrel — 5.56x45mm NATO, 7" Pistol-Length, Black Nitride, 4150 Chrome Moly Vanadium Steel | Model 556P7H50B8R (UPC: 815875019169)
Build a compact, reliable AR-pattern pistol with the Diamondback DB 7" 5.56x45mm NATO Barrel. Precision-machined from 4150 Chrome Moly Vanadium (CMV) steel and treated with a durable black nitride (QPQ) finish, this short barrel is purpose-built for maneuverability, longevity, and easy maintenance. The pistol-length gas system supports dependable cycling in ultra-compact configurations, while the nitride bore and exterior fight corrosion and make clean-up fast—ideal for CQB-style training, range fun, and suppressed builds (when properly tuned).
Why Choose This Diamondback 7" 5.56 Barrel?
Compact performance, real durability: The 7-inch length keeps overall build size minimal without compromising on a duty-grade 4150 CMV material that’s proven under heat and hard use.
Nitride (QPQ) inside & out: The QPQ process increases surface hardness, resists rust, and reduces copper/carbon fouling, so the bore cleans up quickly and wears more slowly over time.
Pistol-length gas for short systems: Optimized gas placement helps maintain reliability on short barrels—especially when combined with the right buffer/spring and (optionally) an adjustable gas block.
5.56 NATO chamber: Works with common 5.56 loads and (per typical 5.56 chamber guidance) .223 Rem ammunition; always verify manufacturer guidance and ensure proper headspace.
AR-15 pattern compatibility: Designed for AR-15 uppers, free-float handguards, and standard 5.56 BCGs for a straightforward build path.
Key Features at a Glance
Caliber: 5.56x45mm NATO
Barrel Length: 7 inches
Material: 4150 Chrome Moly Vanadium (CMV) steel
Finish/Treatment: Black Nitride (QPQ), inside and out
Gas System: Pistol-length
Platform: AR-15 pattern pistols/SBRs (where lawful)
Model: 556P7H50B8R
UPC: 815875019169
Color: Matte black nitride
Builder’s note: Confirm twist rate, muzzle thread, gas journal diameter, and contour for your specific production run to match gas blocks, muzzle devices/suppressor mounts, and preferred bullet weights.
Performance Benefits You’ll Notice
Maneuverability in tight spaces: The short length keeps the front end light for quick transitions and better control during close-in drills.
Cleaner, faster maintenance: QPQ nitride reduces fouling adhesion, helping you spend less time scrubbing and more time shooting.
Heat & erosion resistance: 4150 CMV plus nitride treatment helps resist throat erosion for more consistent velocities session after session.
Tunable reliability: Pairing the pistol gas with an adjustable gas block (highly recommended for suppressed use) and a properly weighted buffer can yield smooth, consistent operation.
Ideal Use Cases
Compact AR-pistol builds where overall length and agility are top priorities
Suppressed configurations tuned for backpressure and ejection pattern control
Vehicle/pack guns (where lawful) requiring portability and fast handling
Range/CQB training with red dots or low-profile optics
Build & Compatibility Checklist
Upper receiver: AR-15 mil-pattern, 5.56 compatible
BCG: 5.56/.223 bolt carrier group, properly headspaced
Gas system: Pistol-length gas tube; verify gas journal (e.g., .750")
Handguard: Short free-float rail with clearance for your chosen muzzle device or suppressor mount
Muzzle device: Match thread pitch and consider options that aid backpressure management on short barrels
Buffer system: Heavier buffers and tuned springs can improve dwell, ejection, and lock-back reliability
Installation Tips
Inspect & prep: Degrease the extension and gas journal; lightly oil mating surfaces.
Torque & align: Install the barrel nut to spec and confirm gas tube alignment through the upper.
Secure gas block: Align to port; dimple/pin as appropriate and apply thread locker per manufacturer instructions.
Headspace check: Always verify with GO/NO-GO gauges before live fire.
Function test & tune: Validate lock-back on empty magazine; adjust gas and buffer weight as needed (especially when suppressed).
Specifications
(Twist rate, muzzle threads, gas journal diameter, and exact contour may vary by production; confirm details prior to ordering companion parts.)
Frequently Asked Questions
Q: Can I shoot .223 Remington through this barrel?
A: Most 5.56 NATO chambers accept .223 Rem. Always follow the manufacturer’s guidance and confirm proper headspace and ammo selection.
Q: Is an adjustable gas block necessary?
A: While not mandatory, it’s strongly recommended for short barrels—especially suppressed—to fine tune reliability, recoil impulse, and ejection.
Q: How accurate is a 7" barrel?
A: Very capable within its intended distances. Barrel length primarily influences velocity rather than intrinsic precision; with quality ammo and parts, expect reliable short-range accuracy.
Q: What legal considerations apply?
A: Know and follow federal, state, and local laws regarding barrel length, pistol vs. SBR classification, transport, and suppressor use before building or modifying any firearm.
Recommended Pairings
Adjustable gas block + pistol-length gas tube
Heavier buffer/spring calibrated for short-barrel cycling
Low-profile free-float handguard for compact ergonomics
Flash hider or brake (or suppressor interface) matched to thread pitch
Red-dot optic for rapid sight acquisition
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Shrink your build without sacrificing reliability. The Diamondback DB 7" 5.56x45mm NATO Black Nitride 4150 CMV Barrel gives you a tough, easy-to-clean foundation for ultra-compact AR-15 projects—suppressed or unsuppressed—when tuned correctly.
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