Daniel Defense DDM4 PDW SBR by Daniel Defense - $2,556 | 2026 Review

Compatibility Tags

family: modern-riflefamily: ar-patterntrigger: ar-fcginterface: picatinny-tophandguard: mlokbarrel: ultra-compactmag-type: stanagthread: 5/8x24

Overview

The DDM4 PDW SBR is the registered short-barreled rifle build of Daniel Defense's .300 Blackout PDW. Mechanically it is the same gun as the braced pistol: a 7-inch cold hammer forged S2W-profile barrel in Chrome Moly Vanadium, chrome lined and HP/MPI tested at a 1:7 twist, running pistol-length direct impingement behind a 4140 low-profile gas block, under a 6-inch MFR XL M-LOK rail with an SLR M-LOK MOD2 plain-front handstop already installed.

The difference is the back end. Where the pistol wears a Maxim Defense CQB pistol brace, the SBR wears the Maxim Defense CQB Gen 7 stock over the same Maxim Defense Enhanced Buffer System, which is a real stock on a registered short-barreled rifle rather than a brace on a pistol. Collapsed, the rifle is 21 inches; extended with the muzzle device it reaches 25 1/2 inches, and it weighs 5.7 pounds.

A 7-inch .300 Blackout barrel keeps subsonic loads subsonic, which is the whole argument for this configuration; powder burn, velocity, and fouling vary with the specific load and barrel. The Daniel Defense Linear Compensator pushes blast forward, and the 5/8x24 threads underneath take a suppressor mount directly. The lower is mil-spec rather than the fully ambidextrous RIII receiver, though it carries an ambidextrous safety selector and the GRIP-N-RIP charging handle is independently ambidextrous. Because it is an NFA item, it transfers through a dealer and buyers must be 21 or older.

Key Features

7" cold hammer forged, chrome-lined S2W-profile .300 Blackout barrel, 1:7 twist, HP/MPI tested
Pistol-length direct-impingement gas system with a 4140 low-profile gas block
Maxim Defense CQB Gen 7 stock over the Maxim Defense Enhanced Buffer System
MFR XL 6.0 M-LOK handguard with an SLR M-LOK MOD2 plain-front handstop
Daniel Defense Linear Compensator on 5/8x24 threads, 17-4 PH stainless, salt bath nitride
Independently ambidextrous GRIP-N-RIP charging handle
M16-profile, chrome-lined, MP-tested bolt carrier group with a properly staked gas key
Ships with a Magpul PMAG 30 AR 300 B GEN M3 and a Daniel Defense full-latch impact case

Detailed Specifications

sku: 02-088-22220-047-c
caliber: 300 BLK
Barrel Length: 7"
Overall Length: 21" - 25 1/2" with muzzle device
weight: 5.7 lbs
Gas System: Pistol length, direct impingement
Twist Rate: 1:7
barrelProfile: S2W (Daniel Defense proprietary heavy barrel)
barrel: Chrome Moly Vanadium steel, cold hammer forged, chrome lined, mil-spec heavy phosphate coated
railSystem: M-LOK (MFR XL 6.0)
Muzzle Device: Daniel Defense Linear Compensator, 17-4 PH stainless steel, salt bath nitride
threadPitch: 5/8x24
Trigger: Mil-spec
lower: Mil-spec with enhanced flared magazine well and rear receiver QD
stock: Maxim Defense CQB Gen 7 Stock
buffer: Maxim Defense Enhanced Buffer System
magazine: Magpul PMAG 30 AR 300 B GEN M3
case: Daniel Defense Full-Latch Impact Plastic Case
nfaStatus: Short-barreled rifle, NFA-regulated transfer