Stock Status: Right To Bear 18" SPR Barrel w/ Ops 12 - 5.56 (Rifle-Length)
This 5.56 chambered 18 inch Special Purpose Profile Rifle-Length Modern Series Barrel is machined from 4150 Chrome Moly Vanadium steel with a QPQ Corrosion Resistant Finish and QPQ coated M4 feed ramp extension. This barrel features a longer .750" profile dimension necessary for proper installation of the OPS Inc 12th model collar and suppressor.
Quench Polish Quench (QPQ) is a specialized type of nitrocarburizing case hardening that increases corrosion resistance. It is sometimes known by the brand name of Tufftride, Tenifer Black Nitride, or Melonite. QPQ is a huge improvement over Chrome Lined barrels. Unlike chrome lining, where the chrome is built up on the surface, QPQ converts the surface without the risk of dimensional build-up. The technique is used when two or more of the following properties are required in a workpiece:
| Barrel | Specifications |
|---|---|
| Caliber | 5.56 |
| Length | 18" |
| Material | 4150 Chrome Moly Vanadium |
| Profile | SPR |
| Finish | QPQ Corrosion Resistant |
| Gas System Length | Rifle |
| Gas Block Journal | .750" |
| Dimpled? | No |
| Twist Rate | 1:7 |
| Muzzle Thread | 1/2x28 TPI |
| Weight | 41oz |
| Barrel Extension | M4 Feed Ramps |
| Target Crown | 11 Degree |
