First Look: 21st Tec TEC-GIII Rifle

An AR-10 style rifle which uses H&K G3 magazines.

posted on December 17, 2023
21st Tech TEC-GIII Rifle

21st Tec has just started selling a new DPMS LR-10 pattern rifle chambered in .308 Win. or 6.5 Creedmoor, the new TEC-GIII rifle. The rifle is designed with a lower receiver which uses the 20 round magazine from a Heckler&Koch G3 but it still uses a traditional AR-10-based bolt carrier group and direct-gas-impingement operating system. The HK G3 is a classic 7.62 NATO roller-delayed blowback battle rifle that was designed during the Cold War. Today, its aluminum or steel 20 round 7.62 NATO magazines can be purchased at low prices and are very easy to find. This magazine accommodates both the .308 Win. cartridges in addition to the 6.5 Creedmoor cartridge. The TEC-GIII rifle is available with either a 16- or 20-inch-long barrel, depending on the caliber.

The 21st Tec TEC-GIII Rifle includes either a 1:10-inch twist .308 Win. barrel or a 1:8-inch twist barrel chambered in 6.5 Creedmoor that measures 20 inches long. The gas blocks found on TEC-GIII carbines and rifles are adjustable to make them more compatible with suppressor use and weigh approximately 8.5 pounds. The rifles are equipped with a mil-spec diameter buffer tube, a 6 position adjustable CCS Carbine stock, a THRIL RTG grip and a 15-inch M-Lok handguard that has a full section of Picatinny rail at 12 o’clock.

21st Tec TEC-GIII Features And Specifications:

  • Caliber: .308 Win. or 6.5 Creedmoor
  • Action: Direct Gas Impingement
  • Weight: 8.5 pounds
  • Overall Length: 35 or 39 inches
  • Barrel Length: 16 or 20 inches
  • Finish: Black or Flat Dark Earth
  • Magazine Capacity: 20 rounds
  • Magazine: HK G3 (ships with 3 magazines) 

21st Tec TEC-GIII rifles in either chambering of .308 Winchester or 6.5mm Creedmoor have an MSRP of $1,500. To learn more about these new DPMS pattern rifles that work with HK G3 magazines, please visit


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