Spartan Rifle

Description

The Spartan Rifle from Rare Breed Triggers delivers a no-compromise AR platform with the tight tolerances and reliability demanded by competitive shooters and professionals. Built as a complete upper receiver assembly, it combines match-grade barrel performance with a battle-ready forged construction.

What you get

• Forged 7075-T6 aluminum upper receiver with M4 feed ramps
• 16″ chrome-moly vanadium barrel with 1:8 twist rate
• Mid-length gas system with pistol-length gas tube (included)
• Rare Breed proprietary nickel-boron coated trigger group
• Type III hardcoat anodized finish (matte black)
• M-LOK compatible 15″ free-float handguard
• Includes forward assist and dust cover
• Weight: 3.2 lbs (upper receiver only)

Build and finish

The Spartan’s upper receiver starts with mil-spec 7075-T6 aluminum forgings machined to tighter tolerances than standard commercial specs. The barrel features a chrome-lined bore and chamber with vanadium steel construction for extended service life under rapid-fire conditions. Rare Breed’s proprietary gas block design ensures consistent cycling with both standard and +P ammunition.

All external surfaces receive a Type III hardcoat anodizing that meets MIL-A-8625F specifications. The handguard uses 6061-T6 aluminum with a proprietary heat-treated M-LOK mounting system that maintains zero better than most aftermarket options. Internal components feature phosphate or nickel-boron coatings where appropriate for reduced friction and corrosion resistance.

Compatible platforms

• AR-15 lower receivers with mil-spec dimensions
• Works with both direct impingement and piston systems
• Compatible with .223 Wylde and 5.56 NATO chambers
• Fits standard AR-15 bolt carrier groups
• Designed for use with carbine or rifle-length buffer tubes

Installation notes

This upper receiver assembly ships ready to mate with any mil-spec AR-15 lower. No gunsmithing required beyond standard takedown pin installation. The gas block comes pre-adjusted for optimal performance with 55-77 grain ammunition but can be field-adjusted with a 3/32″ hex key.

Sunshine Gun Shop stocks the Spartan Rifle alongside compatible BCGs, charging handles, and lower parts kits to complete your build. As with all Rare Breed products, this upper receiver carries a lifetime warranty against manufacturing defects when purchased through authorized dealers.