The .300 Blackout cartridge was developed in the United States by Advanced Armament Corporation as an alternative to the standard NATO 5.56 mm cartridge commonly used in the standard issue rifles of NATO armed forces.
There was a perceived need for a harder hitting cartridge and improved performance over both the 5.56mm rifle cartridge and the 9mm pistol round used in many submachine guns.
The design specification was that the round must still be useable in an M4 platform using the same size magazines as the standard M4 chambered in 5.56mm and provide better high velocity performance than the 5.56mm and better subsonic performance than 9mm.
Figure 1: By Silencertalk [CC BY 3.0 (https://creativecommons.org/licenses/by/3.0)], from Wikimedia Commons. 300 AAC BLACKOUT 125 grain plastic tip, 300 AAC BLACKOUT 125 grain match, 300 AAC BLACKOUT 220 grain subsonic, 5.56mm NATO, 7.62x39mm
You can see in the picture above the size difference between the standard NATO 5.56, while the caliber is significantly larger the length of the cartridge and bullet is the same and so it can be used in the same magazines.
It is comparable in size to the 7.62x39mm round familiar to those of you who shoot AK and SKS rifles, the case length of the .300 blackout is 35mm rather than 39mm though.
Another design criteria for what would eventually become the .300 blackout was that it should produce similar energies to the 7.62x39mm Soviet cartridge and we’ll compare some of those energies here using the 5.56mm NATO as a benchmark:
|3.56 g (55 gr) XM193 FMJBT||993 m/s (3,260 ft/s)||1,755 J (1,294 ft⋅lbf)|
|4 g (62 gr) SS109 FMJBT||864 m/s (2,830 ft/s)||1,801 J (1,328 ft⋅lbf)|
|4 g (62 gr) M855A1 FMJBT||860 m/s (2,800 ft/s)||1,889 J (1,393 ft⋅lbf)|
|4.1 g (63 gr) DM11 FMJBT||856 m/s (2,810 ft/s)||1,796 J (1,325 ft⋅lbf)|
|4.1 g (63 gr) GP 90 FMJBT||850 m/s (2,800 ft/s)||1,679 J (1,238 ft⋅lbf)|
To put these figures in perspective it would be useful to see what happens when a 5.56mm bullet strikes something wouldn’t it;
Ballistic gel tests like the one in the video give a representation of the wounding potential of a round in ballistics grade gelatine that realistically represents flesh. When watched in slow motion these ballistic gelatine tests also give an idea of the temporary wound cavity and energy transfer of the projectile.
The permanent wound is shown in the gelatine after it has come to rest such as in this picture here showing the permanent wound cavity and fragmentation of a .300 blackout bullet;
Figure 2: By Silencertalk [CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0) or GFDL (http://www.gnu.org/copyleft/fdl.html)], from Wikimedia Commons
The slow motion footage though shows how a human or animal target will be affected by the round arriving. You can compare the 5.56mm impact with the 7.62x39mm here;
You can see the significantly increased cavitation effect inside the target compared to the 5.56mm and below you can see the ballistics data;
|7.9 g (122 gr) 57N231 FMJ||730.3 m/s (2,396 ft/s)||2,108 J (1,555 ft⋅lbf)|
|10.0 g (154 gr) SP||641.3 m/s (2,104 ft/s)||2,056 J (1,516 ft⋅lbf)|
|8.0 g (123 gr) FMJ||738.0 m/s (2,421 ft/s)||2,179 J (1,607 ft⋅lbf)|
You can see that the heavier bullets are producing lower muzzle velocities by in some cases 400 ft/lbs of additional muzzle energy. When you look at the .300 blackout you can expect to see something close to 7.62×39 in terms of performance;
You can see that the expansion of the bullet and the temporary wound cavity caused is very similar to the 7.62x39mm with the 110 grain bullets used in the video but the advantage of the .300 blackout is it’s huge versatility and the range of bullets it can handle, check out the ballistics;
|125 gr (8 g) OTM||2,215 ft/s (675 m/s)||1,360 ft⋅lbf (1,840 J)|
|220 gr (14 g) OTM||1,010 ft/s (310 m/s)||498 ft⋅lbf (675 J)|
|78 gr (5 g) Lehigh Defense CQ||2,800 ft/s (850 m/s)||1,358 ft⋅lbf (1,841 J)|
|90 gr (6 g) Barnes OTFB||2,550 ft/s (780 m/s)||1,300 ft⋅lbf (1,800 J)|
You can see straight away that while all the other rounds the bullet weights are fairly consistent whereas the .300 Blackout offers a massive range of ammunition types, and all those represented in the table above are factory rounds, not specialist home loaded ammunition.
The sub-sonic rounds outperform the standard sub-machine gun calibers of 9mm and .45acp quite significantly and offer almost silent shooting with a moderated rifle making it perfect for tactical use and for vermin control at moderate ranges and around livestock that you don’t want to disturb.
Check out some of the ballistics gel footage with the 220gr sub sonic ammunition;
So the .300 blackout does give you a very versatile round to use for a range of military or hunting scenarios. Also from a tactical perspective, and this was part of the design specification, M4’s can be modified very easily from 5.56mm to .300 blackout with a simple barrel and bolt assembly change.
Several of the world’s armed forces have already placed orders for rifles in .300 blackout, or conversion kits for their currently issued firearms, including the USA, UK and Dutch armed forces.
While the blackout beats the 5.56mm at close to mid-range, a .300 blackout carries the same energy at 700 meters that a 5.56mm carries at 500 meters and but at that range there is significant drop to compensate for so its effective range is deemed to be 460 meters.
For this reason, it is not comparable to larger calibers in terms of its range and is really only suitable for short to mid-range shooting. At those ranges though it is extremely versatile, mainly because of the range of ammunition it can handle.
Because it is so versatile though there isn’t going to be one single scope that is suitable for every scenario that you would use your .300 blackout rifle for. While the military design specification for .300 blackout demanded that it be easy to convert M4’s to use the caliber but there are plenty of other platforms for the blackout including ‘pistol’ platforms coming in similar sizes to the Heckler and Koch MP5, with barrels as short as 4.5 inches still producing good results.
Various bolt action rifles such as the Remington 700 and Ruger American can also be found chambered in .300 blackout and provide a longer barrel for slightly longer range shooting for mid-range targets or hunting.
With such a range of weapons available in the caliber with diverse applications, you will need to consider how you are using your weapon and under what conditions so you can choose the best scope for your needs.
- So What Do You Need to Consider When Selecting a Scope for Your .300 Blackout?
- Recommendations for Tactical Applications 300 Blackout Scope
- Recommendations for Vermin and Target Shooting
So What Do You Need to Consider When Selecting a Scope for Your .300 Blackout?
First things first, separate your tactical applications from vermin and target shooting, if you are putting .300 blackout down range through an AR platform with tactical or defensive purposes in mind then you need a scope that matches that philosophy of use.
Something with relatively low magnification that allows fast target acquisition is what you need, potentially something with longer eye relief that gives you a better field of view around the scope for scanning for threats and your next target and for relatively close range shooting within the optimum range of the weapon.
Additionally, your scope will probably need to be compatible with Weaver or Picatinny accessory rails and you will need to choose mounts accordingly, although many tactical aiming systems come with built in mounts so you may not need to shop for these separately.
You will also need to consider that your rifle and scope might need to take significant abuse or be exposed to water, bad weather and extremes of temperature. And will need to choose carefully to make sure you select something robust enough for your needs, this does mean you will need to be realistic about your budget and realize that sometimes quality does cost more.
You may also want to mount additional accessories on the rifle or scope to complement your primary sighting system, perhaps a laser dot or magnifier.
For target shooting and hunting you may well have selected a bolt action rifle instead of using the AR platform, in this case you are likely to be using a more traditional pattern scope and be focusing on precision accuracy rather than fast target acquisition.
You will likely need standard dovetail mounts for a scope on a hunting rifle and will probably want more magnification than most scopes for tactical applications providing more precision on hunting quarry.
Due to the effective range of the .300 blackout being limited compared to larger centre fire cartridges such as .308 and .300 Win Mag you won’t need a massive scope designed for long range shooting but you should always shop for quality.
Recommendations for Tactical Applications 300 Blackout Scope
Be careful when shopping for tactical optics, there are so many ‘airsoft’ scopes and optics out there now that appear at first glance the be a fantastic deal, it’s only when you read in detail that it’s clear they are designed for an airsoft weapon without any real recoil.
They are toys and will not be durable enough to survive the recoil of a centrefire rifle let alone the rough treatment that a scope for a tactical rifle will have to put up with. Shop with care.
Trijicon ACOG 4×32
You can’t shop for tactical scopes without at least considering a Trijicon ACOG, they have become a staple sighting option on military rifles and are very robust and battle proven.
This particular model not only gives you a 4×32 optic with adjustable illuminated reticle, and several reticle options, but also comes with an attached reflex sight mounted on top of the scope.
This gives you the option to use the scope for precise shooting and the reflex sight for closer ranges, snap shooting and suppressing fire. The Trijicon is a high ticket item, with this model retailing at around the $1000 mark but it is true quality and very, very robust. Certainly more robust than most other options.
Durability is something you really do have to consider for your tactical rifle, it might get thrown around in the back of a truck, dragged through mud and water or subjected to shock in the harshest of environments, and this Trijicon won’t let you down.
Aimpoint T2 Micro
Another manufacturer with at least the pedigree of Trijicon, Aimpoint made the first red dot sights back in 1974 and are still going strong today.
This is a tiny optic but is very robust, it doesn’t offer the dual sight feature of the Trijicon with the reflex sight on top but it is a simple package for fast accurate shooting. The illuminated dot and long eye relief is designed for ‘both eyes open’ shooting and it excels at this.
This style scope can cross over the tactical/hunting boundary and they are excellent for running boar and driven ground game as well as for use on shotguns for turkey shooting and other larger quarry.
They can be adapted for more precise shooting by the addition of a magnifier which can be swung on line with the optic when more precision or longer range is required. With the magnifier though you are looking at a package that will cost in the region of $1800.
Without the T2 on its own retails from between $800-$1000 so you are looking at another high priced item but which can’t be faulted in terms of quality and durability. For the more budget conscious though there are other options;
Primary Arms 3x With .330blk Reticle
This Primary Arms optic has a reticle calibrated specifically for 7.62x39mm or .300 blackout to help you adjust for the bullet drop.
The reticle is also illuminated to help you pick up targets quickly and for shooting in low light conditions.
The 3 times magnification is ideal for the kind of ranges that you will be using AR 15 rifles and the bullet drop reticle helps you keep your rounds on target without having to think too hard about it.
This scope represents fantastic value for the money as well and is by no means a ‘cheap’ scope in terms of build quality or capability.
Burris Fastfire III
As part of the design specification for the .300 blackout it had to out perform 9mm so many of the platforms for the calibre are very compact.
These .300 blackout ‘pistols’ tend to feature very short barrels down in the 9 inch region and can be complemented by very compact sights, while not strictly a scope this Burris Fastfire reflex sight provides a very compact and low profile sight option for your weapon.
Recommendations for Vermin and Target Shooting
The absolute silence of the .300 blackout with sub sonic ammunition makes it perfect for vermin control and hunting. It doesn’t have the range or power of more popular hunting cartridges like .30-06 or .270 so wouldn’t be the appropriate caliber for larger games like moose and elk or for longer range target shooting.
With high velocity ammunition, it is ideal for small to medium sized game and deer and I have replaced my .223 rifle with the .300 blackout because I came to mistrust the .223 and wasn’t convinced of it’s killing capability on small deer.
The absolute silence of the round in a moderated rifle with sub-sonic ammunition means I can use it around livestock without disturbing them if I need to control foxes and makes it ideal for deer culls on the smaller deer species where I may have to shoot multiple animals in quick succession, something that is often not possible with the louder ammunition of a .243 or .270.
There are sub sonic loads for other centre fire cartridges of course and there is an argument that the blackout does not provide the versatility of other cartridges. .308 for example with sub sonic loads is as quiet as the blackout and with high velocity ammunition far out performs high velocity blackout ammunition.
However there is not always any need for a full power centre fire rifle cartridge and the blackout is an excellent mid-sized cartridge without the overkill of the .308 or other larger cartridges, it does mean that from a hunting perspective though you can’t really take on larger game and that your range is limited to 4-500 meters.
This is the scope I use on my Remington 700 SD chambered in .300 blackout, it gives plenty of adjustability for taking advantage of the different types of ammunition the .300 blackout offers and features a 50mm front objective lens for maximum light gathering for dusk and dawn shooting.
The finger adjustable focus, windage and elevation turrets are a plus for easily making adjustments. It is a mid to low price scope coming in around the $300-$500 mark from most retailers and offers excellent value.
I would highly recommend it but for a bit more of an investment you could get something with slightly better quality glass.
The higher quality glass and coating on optics by top end optics manufacturers such as Zeiss and Shmitd and Bender do provide a little extra clarity of image and with their lens coatings are more resistant to glare.
Schmidt and Bender 5-24×56 PM II Riflescope
Schmidt and Bender scopes are known world over for the exceptional quality and outstanding craftsmanship that goes into them. They are amongst the very best optics in the world and this scope will do everything and more than you could demand from it with your .300 blackout.
This scope will perform at ranges far beyond the ability of the cartridge and could easily be used with much larger calibers at ranges up to 1000 meters. It also features an illuminated reticle and dial in windage and elevation turrets.
While these features are really aimed at long distance shooters they can be useful for making adjustments at mid-ranges with the blackout to compensate as its trajectory drops off out at the 3-400 yard range.
ATN Day/Night Riflescope
This ATN scope offers the very latest technology to aid the shooter and would be suitable for specialist tactical applications such as night shooting as well as for hunting and vermin control.
It would not be suitable for target shooting at longer ranges but would be perfectly adequate for the ranges you will use you blackout at. Not only does it allow you to shoot both day and night with a single scope but it is very lightweight and features a range of technology to make your shooting easier.
With a Bluetooth link to your phone and features to aid aiming and record the fall of shots it is a fantastic and very advanced package. It will do almost everything except pull the trigger for you.
Vortex Diamondback 4-16×42
Going back to more affordable scopes the Diamondback series by Vortex Optics is another good choice for your .300 blackout and comes in at an even lower price than the Sightron offering at under $200.
However, it’s 42mm front end will not offer the same light gathering capabilities as the Sightron’s 50mm objective lens. However, it is a good choice for your rifle and will be suitable for shooting at long ranges, or at least at the upper limit of the .300 blackouts capabilities.
Remember .300 blackout is not a round suitable for true long range shooting, being effective out to about 400 meters, but this scope will be suitable for that.
I currently have the Sightron S-Tac on my rifle chambered in .300 blackout but have also used the ATN on it and will be putting it back on for some night time fox control over the next few weeks so those are choices that I can thoroughly recommend for hunting purposes.
For target shooting, the Sightron is another fairly affordable option but if you can afford the Schmidt and Bender they are truly a pleasure to use but will be more expensive than your rifle.
For tactical use or for running ground game such as boar Aimpoint sights are the best scope for 300 blackout but they are very specialist and you do need to consider carefully what you will be using your blackout for before you commit to a scope for it.
Travis Mike is a firearm enthusiast and author passionate about all things guns. With 10 years of experience in the industry, Travis Mike has gained a wealth of knowledge on the subject. He is skilled in gunsmithing and tactical training. In addition to professional experience, Travis Mike is an avid hunter and shooter, regularly participating in local shooting ranges and hunting trips.