Sons of Liberty Gun Work’s Scalper Bolt Carrier Group for AR-15

Original price was: $205.00.Current price is: $197.40.

In stock

SKU: SOLGWBCG556-SCALPER UPC: 676821257895

Product Description

Sons of Liberty Gun Works looks at the bolt carrier group as the heart of the gun. If the gas port is the lungs, then the bolt carrier group is the heart. It’s what drives the entire gun.  As such SOLGW crafted their Scalper bolt carrier group with precision and engineered for excellence, this BCG sets new standards for reliability and functionality. Meticulously machined from premium materials, it ensures seamless operation, reduced friction, and enhanced durability.  Building on their industry-leading Carpenter BCG, the Scalper adds FCD’s OCKS Key Screws as an extra layer of enhanced reliability. Incorporating the exclusive Scalper Logo serves as the perfect finishing touch.

  • Precision machined from Carpenter Technology No. 158 chrome-nickel alloy
  • Heat-treated per mil-spec
  • Shot peened per ASTM B851/SAE AMS2430S
  • Vibratory tumbled
  • Individual high pressure/proof (HP) test
  • Full Auto test-fired at assembly
  • Individual magnetic particle inspection ASTM E1444/E1444M (MP)
  • Markings deep laser engraved.
  • Finish: Manganese Phosphate


  • Precision machined from 4340 tool steel alloy per SAE AMS6415T/AMS6484D (vs 4140)
  • Heat-treated
  • Shot peen per ASTM B851/SAE AMS2430S

Extractor Retaining Pin:

  • Precision machined and ground S7 Tool Steel
  • Heat-treated per ASTM A681-08
  • Shot peened per mil-spec print

Extractor Spring:

  • Tactical Springs/Sprinco 5 coil, ASTM Grade A401 Chrome Silicon wire stock
  • Heat-treated
  • Stress-relieved, Molybdenum-Disulfide infused
  • Cryogenic processed (Hidden post winding)
  • Mil-spec black insert/synthetic elastomer extractor buffer (nitrile-butadiene, shore hardness 80+/-5 durometer per MIL-PRF-6855)


  • S7 Tool Steel
  • Heat-treated per ASTM A681-08
  • Shot peened per Mil-Spec

Ejector Spring:

  • Heat-treated
  • Mil-Spec

Gas Rings:

  • Standard stainless steel per Mil-Spec X3


  • Machined from AISI 8620 aircraft quality alloy per ASTM A108/A322-13
  • Full auto profile
  • Heat-treated
  • Carburized/strain relieved, hard chrome bore
  • Precision ground gas key interface
  • Sons of Liberty Scalper Logo deep laser engraved

Gas Key:

  • Machined from 4130 Chromoly steel alloy per ASTM A108/A322-13
  • Heat-treated; hard chrome internal
  • Permatex sealed
  • Grade 8 FCD’s OCKS Modified Key Screws

Cam Pin:

  • Precision machined 4340 Chromoly steel alloy per SAE AMS6415T/AMS6484D
  • Heat-treated/processed per mil-spec
  • Solid film lubricant applied and cured per mil-spec

Firing Pin:

  • Precision machined 8640 steel alloy
  • Heat-treated/processed per mil-spec
  • Hard chrome plate

Firing Pin Retaining Pin:

  • Precision machined from 1038 carbon steel
  • Heat-treated/processed per mil-spec



Technical Information

Caliber 5.56 NATO / .223 Remington
Material Chrome Nickel Alloy , Steel
Color / Pattern

Catalog Location

California Prop 65 Warning

WARNING: This product can expose you to chemicals, which are known to the State of California to cause Cancer and Reproductive Harm. For more information visit

Customer Reviews

Based on 1 review
scalper BCG 👍

This BCG is known for its high quality, and from its appearance I have no reason to doubt it is. Very impressive build quality apparent from visual inspection. I havent been able to put it to use yet but I fully expect it to be amongst the highest quality available and will update this review after I have confirmed that with use.