CMMG Endeavor
The CMMG Endeavor extends CMMG's Radial Delayed Blowback operating system to the full-size AR-15 platform — a 16" rifle delivering the cleaner-running, better-suppressed performance of CMMG's piston-like delayed system in traditional AR-15 calibers. The AR-15 for shooters who want the standard rifle format with CMMG's unique operating system advantage.
Read our full CMMG Endeavor Buying Guide ↓
Endeavor vs. Banshee vs. Resolute
CMMG's Radial Delayed Blowback system appears across three distinct platforms. The Banshee is the compact pistol/SBR on a reduced-scale lower in pistol calibers. The Resolute is the full-size rifle in pistol calibers. The Endeavor is the full-size rifle in rifle calibers — 5.56 NATO, .300 Blackout, .458 SOCOM, and others — using CMMG's Radial Delayed Blowback adapted to standard AR-15 rifle cartridges. If you want CMMG's operating system in a traditional AR-15 caliber with a 16" barrel, the Endeavor is the correct platform.
Radial Delayed Blowback in Rifle Calibers
CMMG's Radial Delayed Blowback system was originally developed for pistol calibers where standard blowback was too violent. Applied to rifle calibers, it functions differently than in the pistol caliber platforms — in 5.56 NATO, the Endeavor uses a variation of the system that manages the bolt opening timing for cleaner extraction and reduced carrier velocity compared to standard direct impingement. The practical benefits are most pronounced in suppressed applications and sustained fire where the Endeavor's system runs cleaner than standard DI alternatives.
Caliber Options
5.56 NATO — Standard AR-15 caliber. The most common Endeavor configuration.
.300 Blackout — Particularly well-suited for suppressed use. The Endeavor's operating system manages subsonic .300 BLK cycling more reliably than standard DI alternatives.
.458 SOCOM — CMMG's Endeavor in .458 SOCOM is one of the most capable large-bore AR-15 builds available — the delayed system handles the .458's significant pressure and impulse more gracefully than standard DI.
6.5 Grendel / .224 Valkyrie — Long-range AR-15 calibers on the Endeavor platform for hunters and precision shooters who want extended effective range in the AR-15 format.
Endeavor Configurations
Endeavor 100 — Entry-level Endeavor with standard components at the most accessible CMMG Endeavor price.
Endeavor 200 / 300 — Enhanced configurations with improved handguard, trigger, and finish options as you move up the tier.
FAQ
What calibers does the CMMG Endeavor come in?
5.56 NATO, .300 Blackout, .458 SOCOM, 6.5 Grendel, .224 Valkyrie, and others depending on configuration.
What is the difference between the CMMG Endeavor and Resolute?
The Resolute is chambered in pistol calibers (9mm, .45 ACP, 10mm). The Endeavor is chambered in rifle calibers (5.56, .300 BLK, .458 SOCOM). Both use CMMG's Radial Delayed Blowback system in a full-size 16" rifle format.
Is the CMMG Endeavor good for suppressed use?
Yes — CMMG's operating system runs cleaner suppressed than standard DI, particularly in .300 Blackout where the Endeavor's delayed system handles subsonic loads more reliably.
Where is CMMG made?
Fayette, Missouri. All CMMG firearms are made in the USA.