Rosco Sage Dynamics K9 Patrol 5.56 Upper with MI G4M 10.5" MLOK Rail

Overt Industries

Was: $558.00
On Sale $499.00
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Rosco Sage Dynamics K9 Patrol 12.5" 5.56 Upper with MI G4M 10.5" MLOK Rail - Custom Build

  • Rosco Manufacturing K9 5.56 NATO Sage Dynamics Patrol Length AR-15 Barrel - 12.5"
  • Overt Industries Thermal Fit Upper Receiver
  • Overt Industries Nitride 4140 Gas Block
  • Patrol Length Melonite Gas Tube
  • Midwest Industries G4M 10.5" MLOK Rail


Assembly Process

This Upper Receiver assembly was properly assembled using Aeroshell 64 on the barrel extension and barrel nut after the threads were properly seasoned. The barrel was also properly dimpled using a BRD Engineering Pro Jig and the gas block set screws were tightened using Rocksett for maximum reliability at high temperatures. The handguard was assembled using Loctite 242 on the rail mounting bolts.

Barrel gas port pin gauged at 0.074" 

Barrel Specifications

Rosco Manufacturing has made a proprietary patrol length gas system to make the dynamics work the best for you on and off the range. This system features an optimized gas port that will function properly when suppressed or unsuppressed. If you are an avid marksman and use your weapon frequently, the K9 continuous taper helps dissipate heat for the best performance possible. If you want to attach new accessories to your rifle but worry about being unbalanced, you do not need to fear that issue with this product. Rosco Manufacturing has shifted the weight to the back of the weapon so that the weight of accessories will balance out. 


  • Features an optimized gas port that functions suppressed or unsuppressed
  • The K9 continuous taper helps dissipate heat
  • The weight has been shifted to the back of the weapon for balance with added accessories
  • It has no 90-degree cuts
  • Comes with a patrol length gas tube
  • It has a nitride barrel and barrel extension finish
  • Weighs 27.05 ounces


  • Barrel Coating - Salt Bath Nitride
  • Barrel Contour - Enhanced Taper
  • Barrel Length - 12.5
  • Barrel Lining - Salt Bath Nitride
  • Barrel Material - 416R Stainless Steel
  • Brand - Rosco Manufacturing
  • Caliber Gauge - 5.56 NATO
  • Feed Ramps - M4
  • Gas Seat Diameter - .750
  • Gas System Length - Patrol
  • Platform - AR-15
  • Thread Pattern - 1/2 X 28
  • Twist Rate - 1:7
  • Weight - 27.05 oz.

Rosco Manufacturing has ensured a quality product to give you the best performance possible. The price and quality is reliable and satisfactory. 

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