Daniel Defense
Daniel Defense DDM4 300 S Upper Receiver Group
10.3" .300 Blackout URG optimized for suppressed shooting with S2W barrel profile and 1:8 twist.
Quick Specs
- Price
- $1,452
- Weight
- 3 lb 10.4 oz
- Brand
- Daniel Defense
- Category
- upper
Features
- •.300 AAC Blackout
- •10.3" CHF S2W barrel
- •Pistol gas
- •DDM4 Rail 9.0" Picatinny
- •BCG & GRIP-N-RIP CH included
Capability Boosts
Recommended For
Compatibility Tags
Overview
The DDM4 300 S Upper Receiver Group is Daniel Defense's purpose-built .300 AAC Blackout platform, optimized for both suppressed and unsuppressed shooting. The 10.3" barrel features Daniel Defense's proprietary S2W (Strength-to-Weight) heavy profile, providing enhanced accuracy and heat dissipation while maintaining reasonable weight.
The 1:8 twist rate is specifically chosen to stabilize both supersonic and subsonic .300 Blackout ammunition effectively. Subsonic 220gr loads perform exceptionally well suppressed, while supersonic 110-125gr loads deliver rifle-like terminal performance at CQB distances. The pistol-length gas system ensures reliable cycling across the full spectrum of .300 Blackout ammunition.
The DDM4 Rail 9.0" handguard provides Picatinny rails for mounting accessories, with included Santoprene rail panels for heat protection and improved grip. Like all Daniel Defense uppers, this package includes the M16 profile bolt carrier group (MPI tested) and GRIP-N-RIP ambidextrous charging handle.
Key Features
- ✓Cold hammer forged 10.3" S2W barrel, chrome lined, HP/MPI tested
- ✓1:8 twist optimized for subsonic and supersonic .300 BLK
- ✓Pistol-length gas system for reliable .300 BLK cycling
- ✓DDM4 Rail 9.0" handguard with Santoprene rail panels
- ✓M16 profile BCG, MPI tested with properly staked gas key
- ✓GRIP-N-RIP ambidextrous charging handle
- ✓Daniel Defense flash suppressor (5/8x24 threads)
Pros
- +Optimized 1:8 twist for full .300 BLK ammunition spectrum
- +S2W barrel profile balances accuracy and heat management
- +Excellent suppressor host with proper gas tuning
- +Complete package with BCG and charging handle
- +Daniel Defense quality and warranty
- +Standard AR-15 lower compatible
Cons
- −Premium pricing for .300 BLK upper
- −10.3" barrel requires SBR or pistol configuration
- −Heavier S2W barrel adds weight vs. government profile
- −Quad rail style heavier than M-LOK alternatives
- −.300 BLK ammunition more expensive than 5.56 NATO
Detailed Specifications
- caliber
- .300 AAC Blackout
- barrelLength
- 10.3"
- barrelProfile
- S2W (Strength-to-Weight) Heavy
- barrelMaterial
- Chrome Moly Vanadium Steel, Cold Hammer Forged
- barrelFinish
- Chrome Lined, Mil-Spec Heavy Phosphate
- twist
- 1:8
- gasSystem
- Pistol Length, Direct Impingement
- gasBlock
- Pinned Low Profile, 4140 Steel, Phosphate
- handguard
- DDM4 Rail 9.0", 6061-T6 Aluminum, Picatinny
- upperReceiver
- 7075-T6 Aluminum, Type III Hard Coat Anodized
- bcg
- M16 Profile, MPI Tested, Chrome Lined
- chargingHandle
- GRIP-N-RIP, 7075-T6 Aluminum, Ambidextrous
- muzzleDevice
- DD Flash Suppressor, 17-4 PH SS, Salt Bath Nitride
- threadPitch
- 5/8x24
- weight
- 3.65 lbs
- madeIn
- USA
Compatible Platforms
+168 morePairs Well With
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4 shared compatibility tags
Wilson Combat
Wilson Combat Protector Carbine .300 HAM'R 16.25"
3 shared compatibility tags
Ruger
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2 shared compatibility tags
Christensen Arms
Christensen Arms Modern Precision Rifle
2 shared compatibility tags
SIG Sauer
SIG Sauer CROSS
2 shared compatibility tags
Sako
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