As you probably know, the AR 15 platform (besides the original), .223 Remington, and 5.56 NATO include a range of conversions in calibers like 9mm, .22 LR or .224 Valkyrie, but if you are looking for a larger caliber, something with a little more bang, there are some options for you to consider. Advances in CNC machining technology and the AR's modular nature have considerably improved the AR platform via cartridge enhancement.
Besides a couple of mid-powerful cartridges such as the 6.5 Grendel, 6.8 SPC, and few of massive thumpers like the .450 Bushmaster, .458 SOCOM, and .50 Beowulf, our favorite is a 300 Blackout, as one of the most successful alternative AR chamberings
The 300 AAC Blackout was not invented to replace the 5.56, but to complement it. Actually, at the British SAS request, it was designed to offer an alternative for the integrally suppressed sub-machine gun H&K MP5SD that shot the pistol 9mm rounds. in addition, the 300 BLK, also known as 7.62×35mm, is a rifle cartridge created to achieve energies similar to the 7.62×39mm AK, matching the ballistics of the 57-N-231 standard AK military 120-grain bullet.
Comparison Chart of the Best 300 Blackout Pistols
PSA 8.5" Pistol-length 300AAC Blackout
PSA 16" 300AAC Blackout MOE M-Lok Rifle
PSA 7.5" Pistol-length 300AAC
Best for the Money
Sig Sauer MCX Rattler Review
What’s Makes the 300 Blackout So Great?
Taking into account the fact that the 300 Blackout, or 300Blk, ammo reaches its max potential in barrels as short as nine inches, it makes 300Blk weapons the ideal CQB and home defense gun.
Another 300 Blackout advantage is flawless functionality with a wide variety of ammo including both supersonic and subsonic loads. The ability to shoot subsonic ammo creates the optimal platform for sound and flash suppressed firearms and provides an AR-15 platform ideal for tactical use, self- defense, and having fun.
Hunters will also appreciate this cartridge because the .223 Remington is illegal to use on deer in some states. For deer hunting, you can think of it as like a .30-30, but in an AR, because the AR-15 upper receivers chamber in the more powerful .30 caliber, it is more suitable and ethical.
Specifying the expensive ammunition as the main downside, some opponents suggest pistol caliber carbines (PCC) as an alternative to the .300BLK pistols and SBRs (short-barreled rifles). However, with the Blackout pistol, you can shoot supersonic ammunition with over 1,000 ft-lbs of energy, which is unimaginable with PCC.
Pistol-Length vs. Rifle - What’s The Difference?
The 300 BLK or .300 AAC Blackout cartridges are designed to be chambered in a standard multi-caliber lower receiver of AR-15 by merely changing only the barrel. Since the .300 BLK is intended to function in much shorter barrels, it uses powders that are suited to burn in the shorter barrel lengths.
The original AR-15 concept was conceived as an assault rifle and was built with a lightweight 20-inch barrel. Shortly after that, to make handling easier, the new military standards required a shorter M4 carbine with the 14.5″ barrel.
As for law-abiding citizens, most civilian rifle barrels are generally required to be 16″ or longer, since the short-barreled rifles (SBR) belong to an NFA Class 3 that requires a citizen to fill out a BATFE Form 4 and pay a $200 tax stamp.
The longer barrel provides a somewhat higher velocity and during testing, it was determined that each inch of barrel lost would cost 25-50 feet per second (fps) in velocity, but didn’t mean that the shorter barrel is not as accurate.
The 300 Blackout cartridge owes its popularity and versatility due to the fact that it can be equally efficient in rifles and pistol-length barrels. Anyway, because of the excessive drop, the max effective range of this ultimate short range thumper is estimated at 300 yards.
If you are hunting medium or large game such as hogs on typical hunting ranges, a hard-hitting, short, light, and quiet rifle chambered in the .300 BLK is far superior. On the other hand, the AR pistol in .300 BLK is a great way to have an SBR without the tax stamp. It also provides you a compact and handy weapon at the same time, while still being a respectably accurate AR platform weapon at 100 yards.
Furthermore, the pistol barrel sizes of 7 or 10.5 inches give the shooter a vast amount of flexibility in confined space shooting making this a great home defense firearm.
How to Choose a New 300 Blackout Pistol?
Nowadays, one popular trend that can't be dismissed is the uptick in popularity for AR-platform pistols, particularly those chambered in a 300 Blackout. As earlier mentioned, the AR pistol category encompassed the guns with barrels shorter than 16 inches and no stock, i.e. they have a different, "pistol" buffer tube that protrudes from the rear of the receiver and does not allow for the attachment of traditional stock.
There are a few things you should consider before choosing a new 300 Blackout pistol. Number one is a pistol-length gas system. Since the 300 AAC Blackouts don't have the pressure of a 5.56 NATO, a pistol-length gas setup will be the most reliable for firing subsonic and supersonic ammunition with or without a suppressor.
However, this shorter gas system causes the firearm to be over-gassed, generating more recoil and louder operation. You can slightly overcome that problem using specialized H2 or H3 buffers that are intended to offset harsh operation.
As the AR pistols endure much higher labor than a standard length gas system, you should look for higher-grade parts than what you would have within a rifle-length system, in order to extend the life of your pistol. The shot-peened bolt and Carpenter No. 158 steel are common in quality BCGs.
Moreover, it means that you should opt for a more durable mil-spec lower receiver machined of 7075-T6 aluminum, which is nearly twice as hard on the Rockwell scale as a commercial 6069-T6 aluminum receiver.
Finally, there is one thing often overlooked and it is ergonomics. Some manufacturers offer a pistol arm brace that enables you to put your arm through the brace and hold it like a pistol. While providing great comfort and function, these braces are essentially a pistol-legal version of the stock, offering shooters the look and feel of an SBR, but without the cost and fuss of a tax stamp.
Review of the Best 300 Blackout Pistols
With the 300 Blackout emerging as one of the most popular alternatives AR chambering, we take a look at five quality AR pistols available in that cartridge.
PSA 8.5" Pistol-length 300 AAC Blackout PSA 8.5"
Palmetto State Armory (PSA) is offering many different configurations of AR-15 based pistols from the barrel length, caliber, gas system, stocks, and handguards. Their 300 AAC BLACKOUT pistols come in barrel lengths ranging from 7 to 12 inches.
The first model in our guide is marketed as a sports, 8.5" long, heavy profile barrel chambered in 300 AAC Blackout with a 1:7 twist rate. The nitride-coated barrel is machined from 4150V Chrome Moly Vanadium steel and attached to forged 7075 T6 aluminum receivers.
The PSA 8″ version is running a pistol length gas system matched by a .750" diameter low profile gas block. It is topped off with an A2-style flash hider and finished with 7” PSA handguard which is MLOK compatible with a short Picatinny rail on top for sights or optics.
Additionally, this handguard’s style comes with a modified aluminum KAK Industries Shockwave pistol buffer tube and Shockwave Technologies polymer blade pistol brace stabilizer.
The lower receiver is Magpul and is also made of 7075-T6 aluminum and marked "MULTI" for caliber, meaning it will function with more than one caliber. It is fitted with a comfortable MOE pistol grip.
BCG (bolt carrier group) is mil-spec (military specification) meaning that is made of shot-peened Carpenter 158 steel and phosphate treated for durability. Like other AR-15 offerings from Palmetto State Armory (PSA), this pistol is one of the most affordable on the market.
While some customers complained of occasional coloring issues, the more serious shortcoming is the lack of sights. Of course, you should also be aware of the recoil, which is a little more than a standard 16″ barrel AR, but still acceptable and not so unpleasant to shoot.
Due to its very short barrel, it is maybe not an "entry-level" firearm, but for sure an indispensable part of every gun collection regardless of income-level or experience.
PSA 16" 300 AAC Blackout MOE M-Lok Rifle
PSA’s rifle with 16" barrel is intended for a budget conscious buyers who want to stay into the world of normal length AR-15 offerings and in short you get what you pay for. That said, the PSA’s nitride 16" barrel is made of 4140 steel and chambered for 300 AAC Blackout cartridge and an M4 barrel extension. The heavy profile barrel features a 1 in 8" twist rate and muzzle with an A2 flash hider.
Interestingly, this rifle configuration firearm utilizes a pistol-length gas system instead of a carbine gas system, because the shorter pistol gas system is most preferred for reliability and when using a suppressor, which the .300 AAC Blackout was made for. This model boasts a PSA 13.5" Lightweight M-Lok free-float handguard and low-profile gas block.
Both forged receivers are quality made using 7075-T6 aluminum and machined to mil-specs. While the lower is marked "MULTI" for caliber, the flat top upper is A3 style receiver which includes forward assist and dust cover. Whereas the shot-peened bolt is made from mil-spec Carpenter 158 steel, the full-auto, M-16 profile bolt carrier is built from 8620 steel, chrome-lined and phosphate-coated.
The PSA 16" 300 AAC Blackout MOE M-Lok rifle is fitted with a Magpul carbine stock, Magpul pistol grip, and the package includes a Magpul MBUS sight set. The buffer tube is made of 7075-T6 aluminum to the mil-spec diameter with six adjustment positions.
Palmetto State Armory (PSA) offers affordably-priced firearms with excellent mil-spec quality that adhere to the standards set forth by the U.S. military. While the mil-spec finished, single-stage fire control group complements this PSA budget option, many first time buyers will get double duty with this firearm designed as standard “gunfighter” rifle and/or home defense rifle.
Best for the Money:
PSA 7.5" Pistol-Length 300 AAC
The short-barreled AR pistols were designed for the Special Forces and represent an absolute weapon of war. If you decide to go for a 300 BLK AR pistol with very short 7.5" barrel, you will get rifle levels of stopping power at close range and almost pistol compactness at 24.5" in overall length. The PSA 7.5" pistol features an SBA3 adjustable stabilizing brace fitted to create a more manageable and accurate AR-pistol platform.
The PSA 7.5" barrel pistol is chambered in 300 AAC and its barrel is machined of 4150V Chrome Moly Vanadium steel. On the manufacturer’s website the twist rate of this barrel was improperly listed as 1:7, actually, it has a twist rate of 1:8.
As you may expect, this heavy profile barrel is matched by the pistol-length gas system and attached to forged 7075 T6 aluminum receivers. Although both parts feature a durable hard coat anodized finish, there are some complaints about sloppy fitting with side to side play.
The specific pistol 7075-T6 buffer tube is fitted with an SB Tactical SBA3 Adjustable Pistol Brace, but its strap may be really tight for average user`s arm. This model comes with upper A3 receiver-type equipped with a lightweight M-Lok free-float nine-inch rail.
As a standard, PSA built in the full-auto profile bolt carrier group with a shot-peened bolt machined from mil-spec Carpenter No. 158 steel. Using a common muzzle thread of 5/8-24, the pistol is equipped with a PSA Fluted Flash Can muzzle device and single-stage, Enhanced Polished Trigger (EPT).
This 7.5" barreled AR pistol in 300 AAC is another great budget option from PSA, which offers a decent balance of features at a low price with few minor issues. Though this Palmetto State Armory AR pistol is really a tactical solution for operators, it will also be a lot of fun and is a serviceable home defense weapon, too.
Best AR Pistol:
Springfield Armory Saint .300 AAC Blackout AR-15 Pistol
Until recently, Springfield Armory has only offered their popular SAINT family of AR-15 rifles and AR-15 Pistol in 5.56. After some critical feedback from customers and the market in general, they released the newest iteration in .300 BLK which represents the next generation of America’s personal defense weapon.
The SAINT AR-15 Pistol features a nine-inch barrel made of Chrome Moly Vanadium (CMV) with a Melonite treatment. The 300 Blackout barrel sports a 1:7″ twist rate and pistol-length gas port with pinned, low-profile adjustable gas block.
The barrel muzzle is topped with the faux suppressor muzzle device, but unfortunately, this package doesn’t include sights. As you would expect in this price range, both receivers are machined from forged aircraft-grade 7075 T6 aluminum. Whereas the upper comes with forward assist, the lower features the company’s premiere Accu-Tite tension system which adds tension between the upper and the lower receivers, overriding any misfitting and minimizing movement.
The upper receiver is equipped with a patent-pending, free-float M-Lok compatible handguard design. The nickel boron (NiB) coated, GI single-stage trigger is an in-house job. Although the manufacturer claims it is an enhanced polished trigger, its travel and pull weight still feel very much like an ordinary GI trigger.
For additional durability, the BCG’s bolt is precision-machined from 9310 steel which is about ~7% stronger than "mil-spec" Carpenter 158 steel. The bolt is shot-peened and magnetic particle inspected and the whole M16 bolt-carrier group is finished in super-hard Melonite.
Instead of a rifle buttstock, the SAINT AR-15 Pistol comes with a carbine H heavy tungsten buffer and rugged SB Tactical SBX-K forearm brace making this weapon compact, fast, and an ideal choice for home defense or CQB.
The Springfield nine-inch barrel is an excellent compact weapon chambered in the battle-proven round and ideally suited for home defense and suppressor work.
With the addition of a rugged SB Tactical SBX-K tactical brace hanging off the buffer tube, it looks and doubles as a sporting type pistol and fills a defensive role also.
Sig Sauer MCX Rattler
Like we mentioned in the introduction, the AR platform-based pistols were spawned from a Special Forces request to develop a lightweight, compact rifle intended to be suppress fired in CQB and urban warfare.
Engineers from Sig Sauer designed a specialized miniature iteration of their MCX Virtus series of rifles chambered in .300 AAC Blackout and called it MCX Rattler PSB (Pistol Stabilizing Brace).
Sig Sauer’s Rattler was engineered around a short-stroke gas operating system rather than a traditional buffer tube. Combining a gas piston actuation system and the 5.5-inch barrel in this pistol, Sig has created a heavy, 5.1-pound, 20-inch long weapon of mass destruction.
However, besides the high price tag, this miniature semi-automatic assault weapon is almost too compact for general plinking and probably isn't the ideal starter AR pistol.
Besides select-fire Rattlers, Sig Sauer also offers a semi-auto only SBR and pistol versions for civilian consumption complemented with a three-position telescoping pistol brace, which allows for an even more compact profile, since the Rattler doesn't require a buffer tube.
Free-floating M-Lok handguards are matched with a PDW mil-spec upper receiver that will fit all mil-spec AR lowers. In order to stabilize the .300 BLK, the Rattler`s hammer forged 5.5-inch barrel features a 1:5 rifling twist.
The free-floating, carbon steel barrel with nitride finish is topped with a two-position, adjustable gas piston system where the muzzle has a three-prong flash suppressor. The modular MCX Rattler’s frame is constructed from 7075 T6 aluminum and uses an enhanced AR-type fire control system and standard USGI-pattern AR-15 magazines.
As the best 300BLK pistol for sale in 2018, the Sig Sauer MCX Rattler offers rifle-like firepower in a package smaller than most SMGs. Utilizing operating controls and basic ergonomics similar to the AR-15, this little 300 Blackout pistol is the pinnacle in defensive/tactical scenarios either for elite operators or experienced civilian shooters.
Rifle-caliber pistols are the trend that can no longer be ignored as the more PDW style firearms find acceptance with the military and consumer audience. Started initially as the elite operators’ chosen full-auto weapon of war, today a number of AR-type semi-automatic pistols have found their place in the hands of civilians.
This genre of weapon is particularly effective when paired with a 300 BLK cartridge which is built from the ground up to be fired in suppressed short-barreled firearms. The 300 AAC Blackout pistol can also be used without a suppressor to shoot full-bore supersonic monsters with AR-15+ impact.