Fully Compatible Manufacturers (Standard AR Nut & Barrel)
These brands follow the traditional blowback AR-15 pattern. Their barrels use a standard AR-15 diameter extension (minus the locking lugs) and their uppers utilize the standard AR-15 barrel nut threads.
Manufacturer
Series/Model
Aero Precision
Palmetto State Armory
Foxtrot Mike (FM)
Angstadt Arms
New Frontier Armory
Spike’s Tactical
Rock River Arms
JP Enterprises
Diamondback
Faxon Firearms
Ballistic Advantage
Stern Defense
JoeBobOutfitters
EPC-9
PX-9 / PA-9
MIKE-9
UDP-9
C-9 / G-4
ST-9
LAR-9
GMR-15
DB9R
Bantam / Complete Uppers
EPC / Complete Uppers
SD Series
Spartan Series
Proprietary Designs (Potential Incompatibilities)
These brands often use a standard "size" thread but have proprietary barrel profiles, extensions, or handguard interfaces that make them incompatible with universal accessories.
1. CMMG (Banshee/Resolute): While they use a standard barrel nut thread, their Radial Delayed Blowback (RDB) system requires a proprietary barrel extension with lugs. A standard blowback barrel will not work in a CMMG RDB upper, and vice versa.
2. Daniel Defense (DDM4 V7P): As you noted, they use a proprietary heavy-profile barrel and a specific handguard mounting interface that often prevents the use of standard aftermarket barrel nuts or accessories.
3. Sig Sauer (M400 Tread): Uses a proprietary barrel nut design and requires a specialized wrench; many standard free-float handguards will not seat correctly without swapping the nut.
4. Angstadt Arms (MDP-9): Unlike their UDP-9, the MDP-9 uses a roller-delayed system which is proprietary to the upper and barrel assembly.
5. Wilson Combat (AR-9): While it uses many standard parts, Wilson often uses a proprietary bolt and tuned barrel extension that can occasionally cause issues with non-Wilson handguard/nut combos.