8.5″ AR-15 Pistol Barrel — 5.56 NATO, M4 Contour, Parkerized (1:7)
Overview: This 8.5″ AR-15 pistol barrel is built from premium 4150 Chrome Moly Vanadium (CMV) and finished in a durable parkerized coating. The M4 contour with a pistol-length gas system and 1:7 twist makes it ideal for modern AR pistol builds and short-barrel configurations in 5.56 NATO. Every barrel receives a 100% inspection — including CMM and air gauge bore checks — and is precision rifled for excellent accuracy at a competitive price.
Key Features
- Caliber: 5.56 NATO (chambered for NATO spec)
- Length: 8.5 inches (pistol-length)
- Profile: M4 contour — balances strength and weight
- Gas System: Pistol-length gas system for suppressed/unsuppressed reliability
- Material: 4150 Chrome Moly Vanadium (CMV)
- Finish: Parkerized for corrosion resistance and low glare
- Twist Rate: 1:7 — optimized for stabilizing heavier 5.56/.223 projectiles
- Quality Control: 100% inspection (CMM, air gauges, visual & machine checks)
- Warranty: Lifetime warranty against manufacturing defects
Why choose this barrel?
The 1:7 twist stabilizes a wide range of bullet weights (especially heavier 62–77 gr and match projectiles), making this barrel a versatile choice for tactical, duty, or piston builds. The M4 contour preserves strength at the shoulder while keeping weight manageable for a pistol platform. Parkerizing provides a durable, battle-proven finish that reduces glare and enhances corrosion resistance.
Compatibility & Build Notes
- Designed for AR-15 uppers configured as pistols (SBR laws may apply for rifles — check local/state/ATF rules).
- Accepts standard AR-15 barrel nuts and gas blocks sized for pistol gas systems.
- Recommended to have a qualified gunsmith perform headspace check and final assembly if you are not experienced.
Inspection & Quality Assurance
All finished barrels go through a rigorous 100% inspection process. Measuring equipment includes coordinate measurement machines (CMMs) and air gauges for bore dimensions, plus visual and machine inspections to ensure concentricity and chamber spec accuracy. The result is a reliable, factory-tested barrel you can trust.
Buy With Confidence
Backed by Mid State Firearms’ lifetime warranty and customer support. If you have questions about fitment or installation, contact us or check our build resources:
- Browse other 5.56 NATO barrels & accessories
- How to choose the right AR-15 barrel — guide from Mid State Firearms
- Questions? Contact Mid State Firearms
- View our full shop
Specs (Quick Reference)
| Caliber | 5.56 NATO |
| Length | 8.5″ |
| Material | 4150 Chrome Moly Vanadium (CMV) |
| Finish | Parkerized |
| Profile | M4 contour |
| Twist | 1:7 |
| Gas System | Pistol-length |
| Warranty | Lifetime |
Note: Always verify local laws for pistol vs SBR configurations. Do not order restricted items to prohibited jurisdictions — see our terms & conditions and FAQ for shipping and transfer policies.
sound of freedom – This was a great set up. I loved being able to customize the set up. Only issue I had was my own fault as a newb to building these. I used a heavy barrel in a slim hand guard. It makes adding attachments tough with clearances. Hoping someday to also get an AR10 from here.