Details
Undercurrent 16 Inch Carbine Gas 1:9.45 7.62x39 AR 15 Freefloat M Lok Handguard Rifle Upper Build Kit
The Undercurrent 16 inch upper build kit delivers a 7.62x39 setup built around a 16.25 inch nitride finished barrel with 1:9.45 twist and carbine length gas system. The 15 inch freefloat M Lok handguard provides modular mounting surfaces while maintaining a lightweight profile. This upper build kit includes the upper assembly with barrel and handguard. BCG and charging handle are not included.
Key Features
- 16.25 inch barrel, 4150 Chrome Moly Vanadium steel, nitride finish, 1:9.45 twist rate, 7.62x39 chambered
- AR-15 upper receiver with M4 feed ramps, 7075 T6 aluminum, anodized finish
- 15 inch freefloat M Lok handguard
- Micro low profile gas block, 0.75 diameter, steel with phosphate finish
- Carbine length gas tube optimized for 16.25 inch barrel
- GI birdcage flash hider, 5/8x24 thread pitch
- 7.62x39 caliber, AR-15 platform
Perfect For
- AR-15 builders seeking 7.62x39 caliber conversion
- Shooters wanting AK caliber in AR platform
- Budget conscious builds using widely available 7.62x39 ammunition
- Range and hunting applications
7.62x39 Caliber Configuration
The 7.62x39 chambering provides an alternative to 5.56 NATO, offering heavier projectiles and different ballistic characteristics. This caliber uses widely available and typically less expensive ammunition compared to many rifle cartridges. The 16.25 inch barrel length provides full powder burn for 7.62x39 while maintaining maneuverability. The 1:9.45 twist rate stabilizes standard 7.62x39 projectiles effectively across common bullet weights.
Nitride Finished Barrel
The barrel features 4150 Chrome Moly Vanadium steel construction with nitride finish. Nitride treatment penetrates the steel surface, providing wear resistance and corrosion protection while maintaining tight tolerances. The carbine length gas system provides reliable cycling with standard 7.62x39 ammunition. The 5/8x24 thread pitch is standard for 7.62x39 muzzle devices.
Freefloat M Lok Handguard System
The 15 inch freefloat M Lok handguard extends nearly to the muzzle device, maximizing usable mounting length. M Lok slots allow modular accessory attachment while maintaining a slim profile. The freefloat design eliminates contact with the barrel, allowing the barrel to vibrate freely for improved accuracy potential. The 15 inch length provides ample rail space for lights, grips, and other accessories.
M4 Feed Ramps for Reliable Feeding
The upper receiver features M4 feed ramps machined into the receiver extension. These extended feed ramps guide cartridges smoothly from the magazine into the chamber, reducing feeding issues with 7.62x39 ammunition. M4 feed ramps are essential for reliable function with this caliber in the AR platform.
Carbine Gas System
The carbine length gas system on a 16.25 inch barrel provides reliable cycling with 7.62x39 ammunition. Micro low profile gas block with phosphate finish keeps the sight plane clean under the handguard. The carbine gas system balances reliable function with manageable recoil impulse.
Upper Build Kit Components
This upper build kit includes the upper assembly with barrel and handguard. BCG and charging handle are not included. The upper receiver is constructed from 7075 T6 aluminum with anodized finish for corrosion resistance and durability. Compatible with standard AR-15 lower receivers chambered for 7.62x39.
Follow safe handling and manufacturer instructions. BCG and charging handle are not included. Requires 7.62x39 specific bolt carrier group and magazines. Ensure compatibility with your lower receiver and magazine system. Ensure compliance with all applicable laws.
