16" 458 SOCOM Complete Upper for AR-15 with Genuine Tromix Bolt, Nitride BCG, Charging Handle, HBAR Barrel and 15" M-LOK Rail
This 16" 458 SOCOM complete upper features a genuine Tromix .458 SOCOM bolt assembly engineered specifically for the cartridge and designed to address common feeding and cycling issues associated with .458 SOCOM AR-15 builds. The Tromix bolt is paired with an M16-profile nitride carrier, creating a premium BCG configuration for this big-bore upper. A chrome moly HBAR barrel, carbine-length gas system, 15" free-float M-LOK handguard, compensator, and 7075 aluminum charging handle complete the assembly. Each Tromix bolt is professionally headspaced with its barrel using Manson GO and NO-GO gauges before the complete upper leaves Ballistic Barn in Texas.
Quick Glance:
Caliber: .458 SOCOM
Platform: AR-15
Configuration: Complete Upper with BCG and Charging Handle
Barrel Length: 16 inches
Barrel Material: Chrome Moly
Barrel Profile: HBAR
Barrel Finish: Parkerized
Twist Rate: 1:14
Barrel Extension: Standard AR-15 Big Bore Barrel Extension with Single Feed Ramp
Muzzle Threads: 5/8x32
Gas System: Carbine Length
Gas Block: .750" Low Profile - Nitride Treated
Handguard: Gen 3 15" Free-Float M-LOK Rail
Upper Receiver: Big Bore Forged 7075-T6 Aluminum
Muzzle Device: Compensator with Crush Washer
Bolt: Genuine Tromix .458 SOCOM Bolt Assembly - 9310 Steel
Bolt Carrier Group: Included - M16 Profile Nitride BCG with Genuine Tromix Bolt
Charging Handle: Included - AR-15 Mil-Spec 7075 Aluminum
Headspace: Tromix Bolt Professionally Headspaced with Manson GO and NO-GO Gauges
Assembly: Fully Assembled Complete Upper Receiver
Full Details:
Big Bore Upper Receiver:
The AR-15 big bore upper receiver is forged from 7075-T6 aluminum and includes the forward assist and dust cover assembly installed. It features a matte black hardcoat anodized finish meeting MIL-A-8625 Type III Class 2 specifications.
16" 458 SOCOM Chrome Moly HBAR Barrel:
At the center of this 458 SOCOM complete upper is a 16" chrome moly HBAR-profile barrel with a 1:14 twist rate and Parkerized finish. The barrel features 5/8x32 muzzle threads and a standard AR-15 big bore barrel extension with a single feed ramp.
Gen 3 15" Free-Float M-LOK Handguard:
The upper features a lightweight Gen 3 15" extended rifle-length narrow-profile free-float M-LOK handguard machined from 6061 aluminum. M-LOK mounting slots run along the 3, 6, and 9 o'clock positions, providing mounting space for compatible accessories. The handguard features a matte black hardcoat anodized finish meeting MIL-A-8625 Type III Class 2 specifications.
Carbine-Length Gas System:
The 16" 458 SOCOM barrel is configured with a carbine-length gas system and .750" low-profile gas block with Nitride treatment.
Compensator:
The 5/8x32 threaded muzzle is fitted with a compensator and crush washer.
Genuine Tromix .458 SOCOM Bolt Carrier Group:
This complete upper includes an M16-profile nitride bolt carrier group equipped with a genuine Tromix .458 SOCOM bolt assembly. Tromix developed its .458 SOCOM bolt specifically for the cartridge, incorporating design features intended to address common feeding and cycling issues encountered with .458 SOCOM systems.
Genuine Tromix Bolt:
The Tromix bolt is machined from a single piece of aircraft and bearing-quality 9310 alloy steel. It is properly heat-treated, precision ground, shot-peened, MPI tested, and finished with a manganese phosphate coating. The bolt is designed specifically for .458 SOCOM and is professionally headspaced with the barrel used in this complete upper.
M16-Profile Nitride Carrier:
The M16-profile carrier is machined from aircraft and bearing-quality 8620 steel, properly heat-treated, precision ground, and finished with nitride for surface durability and corrosion resistance.
Enhanced Extractor:
The BCG uses a one-piece billet, fully machined enhanced extractor with a phosphate coating. The extractor is designed to provide reliable extraction in the large-bore .458 SOCOM system.
Firing Pin, Cam Pin and Ejector:
The firing pin is machined from 8740 steel, precision ground, and chrome plated. The BCG also features a nitride cam pin along with an S7 tool steel ejector and extractor retaining pin for strength and durability.
Gas Key:
The 4130 steel gas key features a nitride finish and is precision staked using a hydraulic staking machine. Grade 8, properly heat-treated carrier key screws with T25 drives provide secure fastening.
Charging Handle:
The included AR-15 Mil-Spec charging handle is precision machined from lightweight and durable 7075 aluminum for dependable operation and long service life.
Professional Headspacing:
The genuine Tromix .458 SOCOM bolt included with this complete upper is professionally headspaced with the barrel using Manson GO and NO-GO gauges. The bolt and barrel are checked together before the assembled upper leaves Ballistic Barn in Texas.
Ready to Install:
This 16" 458 SOCOM complete upper arrives fully assembled with the M16-profile nitride BCG, genuine Tromix .458 SOCOM bolt assembly, and AR-15 Mil-Spec 7075 aluminum charging handle included. It is designed for use with compatible standard-dimension AR-15 lower receivers.
IMPORTANT .458 SOCOM LOADING NOTICE
Always load .458 SOCOM ammunition from a magazine. Do not place a cartridge directly into the chamber through the ejection port and release the bolt onto it. Doing so may create a risk of an unintended slam fire when the bolt closes.
Important: This complete upper receiver assembly is not a firearm and can be shipped directly to you. No FFL is required.
Ballistic Barn AR-15 complete uppers are assembled in Texas using quality AR-platform components. Each complete upper is individually inspected, and the included bolt is professionally headspaced with its barrel before shipment to help provide proper fit and dependable operation.
