This DDM4 from Daniel Defense is a prototype. Available in March 2013, this is a short-barreled offering with a 10.3-inch tube shrouded by the company’s new nine-inch rail. And what makes this rifle a complete trendsetter can be largely credited to the fact it arrived chambered in .300 Blackout wearing an AAC suppressor-ready flash hider. After a long year of disappoints, I can finally say that we’ve found a subsonic-shooting platform in this caliber that you can actually depend on.
Why Does the .300 BLK Matter?
The .300 Blackout (.300 BLK) we know today was initially developed by Advanced Armament Corp. (AAC) for use by U.S. Special Operations needing .30-caliber performance from a short-barreled rifle (SBR) in suppressed applications. In many documented cases overseas, the 5.56 just wasn’t getting it done. Though everyone in the Spec Ops community seems to know that bearded fellows in Multicam and Merrells are evaluating the Blackout (the real reason it’s still tough to find ammunition), no one will go on record to talk about it. (They probably learned some lessons in the last 10 years when these guys originally tried to adopt the 6.8 SPC and told everyone.)
So, mum’s the word. I now leave it to the commercial firearm industry to speculate what the clandestine side of the U.S. military wants with .300 BLK. All I can say is that to appreciate the Blackout and what the cartridge will do, you have to understand what it won’t do.
The .300 BLK isn’t the perfect cartridge. It requires a number of important considerations. I’ve shot more .300 BLK than most in my line of work from virtually every ammunition brand out there. It’s dirty. In my experience it usually requires twice the amount of effort to clean a rifle as one chambered in 5.56 to the same degree of cleanliness. And it’s finicky. Although every manufacturer claims that you can use this cartridge with any 5.56 magazine, I’ve found this simply isn’t true. Different makes of rifles seem to prefer different types of magazines (if they reliably feed at all). Most important, rifles with carbine-length gas systems often choke as they try to feed the heavyweight subsonic loads if they aren’t suppressed. And don’t even get me started on bullet-drop differences you’ll need to chart past 100 yards if you intend to shoot a combination of various loads.
The advantages that Special Operations and even hunters are interested in start with the lack of logistical issues in obtaining such a substantial increase in muzzle energy over a 5.56. Don’t get me wrong, I love what the 6.5 Grendel and the 6.8 SPC offer, but you don’t need to hog out the bolt face to shoot .300 BLK. It uses the same bolt because the cartridge rim is the same as the 5.56. (While working as an armorer for Blackwater, I saw a number of high-round-count 6.8 carbines snap a bolt lug.) And if you hoard magazines, you’ll appreciate the fact that .300 will run in most 5.56 magazines without special followers (as needed for the 6.5 and 6.8).
Enter Daniel Defense
Until this rifle arrived on the scene, the advantages of the .300 Blackout were largely theory, in my book. Most rifles I’ve shot didn’t run 5.56 magazines universally, and only a couple of them would run both supersonic and subsonic loads. Looking back on this, I attribute these failures to a lack of build quality (there are always issues on a new product launch) and without a full understanding as to what the .300 Blackout should do.
The subsonic .300 Blackout can facilitate a healthier shooting experience with regard to your hearing, whether on the range or for personal defense. Unlike other cartridges, you don’t get high muzzle velocities when you SBR a .300 Blackout. Due to the pistol powders used in most of these loads, subsonic .300 ammunition generates lower pressure and emits less unburnt powder that turns into flash beyond the muzzle. And when you attach an AAC suppressor to this Daniel Defense, any hint of flash signature all but completely disappeared during low-light testing.
A short rifle like this lightens weight and improves handling. Attach a suppressor to this DDM4 with 10.3-inch barrel and the overall length is the same as an unsuppressed AR with 16-inch barrel. Being that it’s chambered in .300 BLK, you don’t lose ballistic effectiveness when you shorten the barrel and you don’t create the similar effects of a stun grenade should you have to fire it within closed quarters. So one could argue that this suppressed Daniel Defense SBR in .300 is the best home-defense gun one could ask for.
This rifle isn’t over-the-top. It features common furniture like the Magpul Original Equipment (MOE) collapsible carbine stock and A2 pistol grip. In standard configuration, the controls are pretty typical with a non-ambi selector, magazine release and bolt catch. And though it doesn’t feel gritty and long, the mil-spec trigger is simply a mil-spec trigger. The charging handle doesn’t have an extended lever, and the ejection port doesn’t display a message when it flips open. This is a simple, yet functional entry into the world of Blackout and SBRs.
Sitting on top of the finely executed Picatinny rail uninterruptedly bridging the upper receiver and fore-end are a set of Daniel Defense backup sights. They slide on either end of the rifle and are affixed by hex-head screws for semi-permanent placement that co-witnesses with just about every red dot and low-powered magnified optic you’d want to attach.
SBR users may ask the obvious question: Why a 10.3-inch barrel? Why not a 9.5 or something on the longer side of 11 plus? The answers lie in understanding its form, function and cycling. Daniel Defense has built a lot of experience in SBRs with popular models like the Mk18. They’ve studied how to increase reliability with different loads and how to run the gun with and without a suppressor.
“We’re getting great groups with this 10.3-inch barrel, incredible groups,” says Jordan Hunter, director of marketing for Daniel Defense. “We wanted to leave enough room to easily attach a can on this rifle with this 9.0 DDM4 rail, so we knew we’d have to have a barrel that was a little longer.”
The DDM4 300 SBR Blackout gives the shooter a .30-caliber projectile fired from an AR platform without the need to increase receiver size, magazine type or bolt (like all of the new AR-10 rifles coming out). Though the dimensions and handling characteristics are similar to a 5.56-chambered rifle, this Blackout offers its user comparable ballistic qualities as the .308 Win. and venerable 7.62×39. Unlike AR-10-type rifles, you’re not sacrificing magazine capacity or subjecting yourself to additional heft. And felt recoil is similar to shooting a 5.56, if not a little less with certain subsonic loads. (Check out the Federal and American Eagle 220-grain OTM.)
Range results revealed that this .300 Blackout can be shot suppressed and unsuppressed utilizing most available supersonic and subsonic ammunitions. Daniel Defense warned us that unsuppressed firing with subsonic ammo can lead to failures to feed, failures to eject and failures to fire and is not recommended. Considering that when customers start shooting this rifle for themselves, they’ll undoubtedly attempt to shoot subsonic ammunition unsuppressed, we did, too. Surprisingly, after more than 250 rounds fired, we only experienced a single failure to eject. Daniel Defense suggest that if anyone insists on shooting subsonic ammunition in a carbine gas system unsuppressed, try utilizing an “H”-weight buffer or other lightweight buffer for more reliable operation.
I’m not the type to manipulate my range data for the benefit of anyone. Unfortunately, many four-shot, one-hole clusters were blown open by my inability to keep it all together for my fifth and final pull of the trigger. The stars did seem to align a few times, most notably with my third group testing Black Hills’ 125-grain OTM (Open Tip Match) load with a suppressor attached. That .76-inch group was like scoring every number on a Mega Millions jackpot. Regardless, for a rifle with this barrel length, these are very consistent and, in some cases, incredible results.
From this point on, the DDM4 300 SBR is the benchmark by which I’ll judge other 300s.
Look for the Daniel Defense DDMR 300 SBR in the newest issue of Book of the AR-15, a special edition dedicated to all rifles, optics, and ammunition related to the current .300 Whisper and .300 Blackout phenomenon. Pre-order your copy at the InterMedia Outdoors Store today!