Calibers: 22 LR, 22 ARC, 4.6x30mm (2026), 5.56 NATO, 5.7x28mm, 6mm ARC, 6.5 Grendel, 6.5 Creedmoor (2026), 300 Blackout, 308 Win., 7.62x39mm, 338 ARC (2025), 350 Legend, 8.6 Blackout (2025), 9mm Luger, 40 S&W, 10mm (2026), 45 ACP. The Mk4 is the carbine-length AR-15 direct-impingement platform. The Mk3 platform (AR-10) is based on the LR-308/DPMS Gen 1 high-pattern design. Pistol-caliber-carbine designations include MkG, MkGs, Mk9, Mk17, and Mk57. The Mk47 designation is for the 7.62x39mm chambering. Weight for the 5.56 MK4 is 6.4 lbs.; length is 32.5″. Add $150 for 5.7x28mm, 9mm; add $175 for Mk9 9mm with Colt-style SMG magazines. Fixed ejector (FE) models added 2025. Values are for the Resolute MK4 5.56 NATO, 16.1″ variant; add 16% for the Resolute FE MK4 9mm, 16.1″ variant.