17 Design & Manufacturing 17DM-15 .300 AAC Blackout Custom AR-15 with Seekins Upper/BCG, BCM 16.5 in Barrel, Aero ATLAS S-ONE, CMC Flat Trigger, ASR Brake
This custom .300 AAC Blackout AR-15 pairs a 17 Design & Manufacturing billet lower with a Seekins Precision slick-side upper and Seekins BCG, anchored by a Bravo Company barrel and an Aero Precision ATLAS S-ONE M-LOK handguard. It adds practical upgrades throughout, including a CMC flat-bow trigger, Radian Raptor-LT charging handle, ambidextrous safety, and an ASR-type 3-port muzzle brake. The Magpul CTR stock and MOE K2+ grip round out a clean, purpose-built configuration with a bright, excellent bore.
Condition
Overall Condition: Very good condition, showing only light, superficial signs of prior handling or use.
Bore Overall Condition: Excellent - Clean, mirror finish, no signs of wear.
Bore Rifling: Excellent Rifling - Sharp lands and grooves.
Specific Condition Details: This rifle shows minimal handling marks on external surfaces. Please review the photos for a close look at condition details.
What’s Included
- 1x 30-round Magpul PMAG polymer magazine (marked 5.56x45)
- M-LOK rail cover panels (installed)
- Low-profile M-LOK hand stop (installed)
- M-LOK QD sling socket (installed)
This build centers on a 17 Design & Manufacturing billet lower receiver with an integral trigger guard and flared magwell. The receiver is marked with the 17 logo, "MOD: 17DM-15," and "CAL: MULTI." Up top is a Seekins Precision slick-side upper that deletes the forward assist while retaining a brass deflector for clean ejection.
The 16.5-inch Bravo Company barrel is threaded and capped with an ASR-type 3-port muzzle brake, providing a quick-attach interface for compatible suppressor systems. An Aero Precision ATLAS S-ONE M-LOK handguard keeps weight down while offering M-LOK slots and short 12 o’clock Picatinny sections for minimal, focused accessory mounting.
Controls and internals are upgraded for performance and handling. A CMC flat-bow trigger delivers a crisp, consistent break. The charging system is the Radian Raptor-LT, and the safety selector is ambidextrous. A Seekins Precision bolt carrier group complements the Seekins upper for a matched operating core.
Ergonomics are addressed with a Magpul CTR adjustable stock on a carbine receiver extension and a Magpul MOE K2+ pistol grip. Included M-LOK rail covers, a low-profile hand stop, and a QD sling socket are already installed. This direct-impingement AR-15 pattern rifle in .300 BLK has a 30+1 capacity and uses standard AR-15 magazines; the included PMAG is marked 5.56x45, reflecting typical magazine compatibility with .300 BLK.