FORT WORTH, TEXAS – San Tan Tactical is expanding its 1836 Series with the introduction of the Ironclad barrel lineup. Featuring four configurations in 5.56 NATO and 6mm ARC, the new series gives builders additional options for their 1836 platform.
The Ironclad lineup includes 11.5″ and 16″ 5.56 NATO barrels, along with 12.5″ and 18″ 6mm ARC barrels. Each configuration features a purpose-matched gas system and a durable Black Nitride finish.

The featured 12.5″ 6mm ARC Ironclad barrel is designed to bring the capabilities of the 6mm ARC cartridge to a compact platform. Precision-machined from 4150 steel, it features a straight-fluted profile that reduces overall weight while increasing surface area for heat dissipation.
The 6mm ARC barrels feature a 1:7.5 twist rate and 5R rifling profile designed to support bullet stabilization while helping reduce jacket deformation. The 12.5″ configuration uses a mid-length gas system, while the 18″ configuration features a rifle-length gas system.

Attention to detail extends throughout the manufacturing process. Ironclad barrels feature honed and polished chambers, hand-polished feed ramps, factory-dimpled .750″ gas block journals, and NTF-coated barrel extensions. Every barrel undergoes 100% quality control inspection and Magnetic Particle Inspection (MPI).
All four configurations feature a Black Nitride (QPQ) finish for corrosion resistance and added protection against wear.
With four initial configurations, the 1836 Series Ironclad lineup gives builders more choices in barrel length, caliber, and gas system configuration. San Tan Tactical will continue developing the 1836 Series with additional products and configurations in the future.
1836 SERIES IRONCLAD BARREL LINEUP
5.56 NATO – 11.5″ Carbine Length
• SKU: STT-1836I-115B-556-N
• Carbine-length gas system
• Black Nitride finish
5.56 NATO – 16″ Mid Length
• SKU: STT-1836I-16B-556-N
• Mid-length gas system
• Black Nitride finish
6mm ARC – 12.5″ Mid Length
• SKU: STT-1836I-125B-6ARC-N
• Mid-length gas system
• Black Nitride finish
6mm ARC – 18″ Rifle Length
• SKU: STT-1836I-18B-6ARC-N
• Rifle-length gas system
• Black Nitride finish
12.5″ IRONCLAD 6MM ARC TECHNICAL SPECIFICATIONS
Specification Detail
Caliber 6mm ARC
Barrel Length 12.5″
Weight 1 lb. 14 oz.
Material 4150 Steel
Profile Straight Fluted
Twist Rate 1:7.5
Rifling 5R
Chamber Honed & Polished
Feed Ramps Hand-Polished
Gas System Mid-Length
Gas Block Journal .750″ Factory Dimpled
Barrel Extension NTF Coated
Muzzle Threads 5/8×24 TPI
Finish Black Nitride (QPQ)
Inspection 100% QC & MPI
SKU STT-1836I-125B-6ARC-N
AVAILABILITY
The 1836 Series Ironclad barrel lineup will be available through San Tan Tactical and its authorized dealer network.
For additional product information, visit www.santantactical.com.
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