Daniel Defense has introduced a new short-barreled rifle (SBR) chambered for the potent 300 Blackout cartridge.

The DDM4 300s is a nimble looking little machine built around a 10.3-inch barrel. It uses standard 5.56mm bolts and magazines, making interchangeability with the MSRs you already own totally possible.

According to Daniel Defense, the 300 Blackout round has proven to be “extremely efficient in short-barrel rifles, yielding superior ballistics over the 7.62x39mm round.”

This piece from explains exactly why the 300 BLK is well-suited for shorter barrels than 5.56 rounds, with author Nick Leghorn saying the longest useful barrel length for the round is nine inches.

“Nine inches of barrel will give you the perfect balance of light weight and velocity with the 300 BLK cartridge,” Leghorn writes. “It was designed to burn in short barrels and anything more is really just excess weight.”

It would seem the 10.3-inch barrel on the DDM4 seems to be right in the sweet spot Leghorn describes.

After all, the .300 AAC Blackout cartridge was designed to be used in M4s with carbine-length barrels with the goal of achieving similar ballistics to the 7.62x39mm cartridge, which proved a difficult-to-manage chambering for MSR-plaform rifles with standard NATO magazines.

Daniel Defense delivers the rifle with all the necessary features. The lower receiver is mil-spec and CNC machined from 7075-T6 Aluminum, with an enhanced flared magazine well and a QD swivel attachment point at the rear of the receiver. It’s hard-coated and anodized.

The upper is also mil-spec with indexing marks and M4-style feed ramps. It’s machined from the same aluminum as the lower with the same finish.

The barrel is cold-hammer-forged chrome moly vanadium steel with a 1:8 twist and a salt bath nitride finish.

The pistol-length gas system is direct impingement with a pinned low-profile gas block

The DDM4 comes with a Daniel Defense Flash Suppressor made from stainless steel with a finish to match the barrel.

It doesn’t come with any sights, just a full-length top Picatinny rail so you can attach whatever sights or optics you want. It also comes with rails at the 9, 3, and 6 o’clock positions on the handguard with DD rail panels made from Santoprene to cover sections not in use.

Of course, this SBR is a regulated item by the National Firearms Act (NFA) and requires a special tax stamp from the BATFE to purchase, if it isn’t otherwise outlawed in your state, similar to purchasing a suppressor or a pistol with a stock.

The DD website says the SBR is available now and sells for $1,749.

Get the full specs here.

The DDM4 300 joins the DDM4 ISR rifle, also chambered in 300 BLK.