300 BlackoutUpdated super magnum, tacti-cool ultra-cartridges come out every few years. It’s virtually impossible to see which ones will last and which ones will go the way of the 7mm SAUM . Like many of these new cartridges the .300blk have ties to military service and unlike many of the other cartridges made by the “experts” for the military, the .300blk is being embraced and loved by military units, shooters and hunters alike.

This is because of the cartridges versatility. Being able to stuff just about any of the available .308 bullets into the case and shoot it in an ar15 makes it a dream for reloaders. It can do everything from plinking with cheap FMJ bullets, home defense, to medium game hunting of black bears and large deer.

The .300blk is an awesome upgrade for any ar15 and because it’s made from the brass of the .223 cartridge all you need to change from an ar15 is the barrel. that’s it. The magazines, bolt, upper and lower will work flawlessly. All you need to do is change the barrel.

What is the .300 Blackout?

The .300 blackout can be described as a .223 trimmed down and necked up to .300blk. The finished product is virtually that, but the .300blk’s design parameters include much, much more. 300blk was originally intended to be a replacement of American special operations units’ H&K Mp5 SSD.

This weapon fires a full auto 9mm in a rifle length integrally suppressed barrel. The goal was to get better performance at the same noise signature but with the m4 rifle. They hit it out of the park. The .300blk fires a 220gr bullet at 1000fps and with a suppressor makes it 100% hearing safe with subsonic loads.

The beauty of this round isn’t solely in suppressed fire but with the overall versatility. You can literally change from hearing safe “across the room” loads to full power 300-yard rifle rounds with just the change of the bullet. That’s the whole reason to shoot the .300blk. to be able to do anything you might need with a single rifle.

Why Should I Shoot .300 Blackout?

The .300 blackout in its own right with no comparisons is an awesome cartridge. It gets compared all too often to the .223/5.56 NATO because it was created by trimming and blowing out the case to .30 caliber. While this gives you an idea of the power level it doesn’t give credit to the cartridge’s extreme versatility and wide range of the .300 blackout’s ballistics.

If you’d like to shoot subsonic suppressed ammunition pop in 230gr rounds that have the same energy as a .45acp. Want to go hunting? Load up a 125gr Nosler ballistic tip and you’ve got a 300-yard deer rifle . If you want a home defense gun, screw on a suppressor and have a hearing safe zero flash signature rifle for fending off intruders.

You can do all this by just changing bullets. Keep your rifle, scope, sling and magazines and all you need to do is change ammo. In fact, you can keep loaded mags of supersonic, and subsonic rounds ready to go in your truck or gun safe and be able to do almost anything you could with a rifle.

Finally, if that’s not reason enough to shoot the .300blk it’s designed to be shot through a 9-inch barrel. Every cartridge has a point of diminishing return where the barrel length isn’t worth the energy gain. According to the people who designed the .300blk, Advanced Armament Company , 9 inches is the barrel length they were shooting for full potential. This isn’t to say a 20-inch barrel won’t be faster but you can expect full rifle performance from a 9-inch barrel.

.300 Blackout vs .223

The most obvious difference between the .300blk and the .223 is the caliber. The .300blk uses .30 caliber bullets just like the .308win and the .30-06. On the other hand, the .223 uses .22 caliber bullets that are much lighter and lighter constructed.

The .30 caliber bore is much more suited to hunting medium to large game because it starts out 50% larger in diameter, has as much as four times the mass and much better sectional density. That combined with the plethora of .30 caliber bullets with everything from stout 220gr rounded points, to high ballistic coefficient 125gr spritzers.

This is in stark contrast to all but the most recent of .223 bullets designed for medium game. The .223 has poor sectional density and abysmal ballistic coefficients that lose velocity quickly. That’s the main problem with the .223 cartridge. The lightweight bullets lose velocity quickly but the round relies wholly on high velocity bullets for killing power.

Getting a Rifle Ready to Shoot:

300 Blackout Upper

There’s only thing that needs to change to convert a rifle to .300 blackout and that’s the barrel. The best case scenario is to have a completely separate .300 blackout upper that allows you to shoot both .223/5.56 and .300blk with just the change of a few pins and a new part.

If this is your plan, just the switch of an upper, make sure you have optics for both uppers because switching the optics kind of kills the ability to swap cartridges quickly. Also be sure you have a clean way to store the upper when not using it. Lubricant needs to be in the bolt carrier group channels and dust, sand or debris can build up in the grease and oil.

The other things you may want to consider is marking the magazines and the upper with colored tape or matching engraved symbols. Stories of soldiers jamming .300blk into a 5.56 upper because they mixed up magazines have ended with explosions when the .308 bullet tries to squeeze through the 5.56 sized hole. The case will chamber slightly and WILL detonate when you drop the hammer.

300 Blackout Lower

Nothing has to change for the lower receiver to shoot .300blk. Just be sure the buffer can take the added recoil from the heavier loads. This is not a common issue but if you find yourself having a lot of malfunctions, including with sub-sonic loads, check the buffer weight and spring.

Another consideration is if you are building a title 2 firearm to have an SBR .300blk and you may shoot .223, get a lower receiver marked multi caliber. It’s unclear how much this matters but it certainly can’t hurt and with the ATF these days, we need all the help we can get.


OpticsScopes made for .223 won’t work for .300blk including calibrated iron sights. Standard duplex crosshair scopes will work great, red dot sights are fantastic, but the ballistic calibrated reticle scopes advertised for ar15s won’t work unless they were made for .300blk. Companies like Trijicon make ACOG’s, and VCOG’s for .300blk and they work wonderfully for shooting out several hundred yards with the .300blk.

Standard Iron sights will work but any of the calibrated sets with range ramps built into the rear sight will be very off past 200 yards depending on the load.

Shooting the .300blk Suppressed

The .300blk from its inception was designed to be shot with a suppressor. Using a suppressor with subsonic ammunition gives you power on par with a .45acp, so if you need to shoot anything further away than across the room it’s a waste of time.

Never, ever hunt with subsonic rounds from a .300blk. Not only do they lack energy, they’ll shoot with the trajectory of a thrown rock and are normally made from FMJ bullets. It is hard as hell to hit with subsonic rounds past 50-75yards out of a .300blk and the FMJ bullets they’re made from are illegal to hunt with.

The subsonic fire for the .300blk is a godsend for home defense with a suppressor because it is hearing safe. For anyone who’s never lit off a round in a confined space, let alone a long gun, I will personally attest that you WILL have hearing damage. The .300blk gives you options to save your ears.

.300 Blackout for Hunting

300 Blackout for Hunting

Hunting with a .300 blackout is a bit of touch and go and you have to follow many of the same rules you’d use for similar class rifle rounds such as the 7.62×39 and .30-30. However, the .300blk is a huge step up in ballistic performance in the ar15 for two main reasons; the diameter of the bullet is 50% larger to begin with and it has a substantial increase in bullet mass.

The .300blk is on the larger end of the small bore spectrum making it big enough to ensure reliable quick kills on medium game to large game. It’s a is a huge step up from the .223 because without reliable expansion and full weight retention of the bullet the .223 will not cleanly take deer sized game. The .30 caliber bore can be called upon to kill with little expansion.

The .30 caliber bore also has substantially more bullet mass because of the increased dimensions. This increase in bullet mass helps exponentially in deep penetration. The penetration of a medium intensity .30 caliber bore, which the .300blk is, still beats out .223 caliber high intensity cartridges.

As to specifically using the .300blk for hunting situations, treat it like the .30-30. The .30-30 is regarded as a fine 150-200yard medium game cartridge for hogs, deer and small black bear. The .300 blackout rifle is a fine brush gun, especially as a lightweight ar15, great for stalking and will work in almost all deer hunting situations most hunters find themselves in. A few things to keep in mind about the .300blk for hunting:

· NEVER use subsonic ammunition for hunting. It isn’t suitable for taking game

· Keep ranges below 300 yards no matter if you can hit it or not, the round runs out of energy

· Use a bullet suitable for the game you’re chasing

· Don’t take chances on game. Wait for a good shot that will ensure a clean kill

. 300 Blackout Reloading

Reloading the .300blk is an easy and straightforward process but it does have its quirks. You can buy brass preformed or you can make your own from .223 cases. This involves blowing out the case neck and trimming it to the proper length. It can be time consuming up front but you can save a pretty penny if you do it often. The ability to make your own brass is what helped propel the .300blk out of boutique status early on. Cheap reliable brass could be made instead of having to use a single supplier or pay high prices.

Other than brass availability there are three main reasons the .300blk is great for reloaders. The .300blk uses less powder than the .223, it uses .30 caliber bullets, and it uses fast burning cheap powders. The .300blk uses less powder because it has a smaller case when it gets trimmed and the longer .30 caliber bullets take up more space inside the case. Even though the cartridge uses less powder it operates at higher pressure keeping the velocity high.

The ability to use nearly all the .30 caliber bullets on the market means there’s no limit to the combinations of loads you can roll for the .300blk. Nothing needs to be really said for the .30 caliber bore being as it’s the king of bullet diameters in the US and you can have everything you want in a bullet.

The powders used for the 300blk are consumed in 9 inches of barrel and are really just glorified pistol powders. These powders clean up well, measure well and are just generally great powders to work with. The .300blk is great for first time reloaders because of the amount of options, cheap per round cost, and relative ease of reloading.

300 Blackout for Hunting

Recommended Factory .300 Blackout Ammo

At one point .300blk was a boutique load and it was hard to find good rounds outside of the few companies that loaded it. These days there are more loads than a lot of the old classic magnums. Not only can you find cheap plinking ammunition, that continues to fall in price, you can get a premium bullet loaded to exacting specifications for every job the .300blk does. Here are a few awesome choices:

Barnes Vor-Tex

The Barnes Vor-Tex line of loaded ammo uses bullets from Barnes, a world leader in monolithic lead free bullets. Their best .300blk loading is a 110gr lead free all copper projectile that retains 99% of its weight when shot. This is an ideal hunting round for hogs, large deer and small bears. They also offer a 120gr loading but there’s little discernable difference between the two loads other than ballistic coefficient.

Hornady American Whitetail

Hornady American Whitetail is a lineup of premium ammunition made specifically for whitetail deer hunting. It’s loaded to all the common calibers used in the US for deer hunting, and they now offer a load in .300blk. These rounds use the Hornady interlock round, a non-bonded lead jacketed bullet that features a thick cannelure that helps prevent jacket separation while allowing for violent expansion.

Remington Hog Hammer

The Remington Hog Hammer is a round made specifically for hunting feral hogs. It’s designed around a Barnes all copper monolithic bullet stuffed into a nickel-plated case. The nickel-plated case aids in reliable feeding through ar15’s and especially helps in the field when dirt and grit can slow down the action of a rifle. The all copper monolithic bullet will punch through and take out even the biggest hog with its 99% weight retention and deep penetration.

Silver State Armory Subsonic

Subsonic ammo can be tough to get lethal ammo for. The fact that the round has to travel so slow means it carries low energy. To compensate for this you need a round that will open up quickly and cause as much damage as possible. Because the subsonic ammo for the .300blk is most likely used for home defense you need a round that will stop inside an intruder. This 220gr subsonic Nosler Ballistic Tip does just that, offered by Palmetto State Armory this is a great option for a home defense subsonic round.

Nosler Match Grade Ammo

Nosler is a giant and known for some of the best bullets on the planet, they make bullets for all types of situations including several rounds for .300blk. Their match grade ammo is made for 3 gun or accuracy matches and it’s the best of the best. This match grade ammo is great because of the exacting specifications it’s made to. That allows you to eliminate ammo variability when zeroing a rifle or testing your accuracy skills.

Final Words

The sheer amount of versatility that comes with purchasing a .300blk upper and a few boxes of ammo is staggering. It turns your ar15 into a high powered .30-30 territory for hunting, home defense and plinking. To take full ability and upgrade the firepower of your ar15 to full .30 caliber performance all you need to do is change the barrel of your rifle. The .300blk is the current king of versatile cartridges.

The .300 blackout was born out of a need for special operations but as hunters, sportsman and reloaders adopt this fine rendition of the ar15 the cost of the round will fall and more and more people will have a rifle cartridge they can depend on