300 Blackout Vs 308 Caliber Comparison:

Discussion in 'Tactical & Black Rifles' started by Grumpy, Jul 12, 2021.

  1. Grumpy

    Grumpy The Grumpy Grease Monkey mechanical engineer. Staff Member

    300 Blackout vs 308 Caliber Comparison: Why Intended Purpose Matters
    The 300 AAC Blackout and 308 Winchester are both 30-caliber rifle cartridges that shoot a .308” diameter bullet. However, this is where the similarities end as both cartridges have a different intended purpose.

    In this caliber comparison article, we are going to take a detailed look at both the 300 AAC Blackout and the 308 Winchester. Unlike previous articles, I won’t “crown a winner” because the difference between 308 vs 300 Blackout is comparing apples to oranges.

    Instead, we will take a deeper look into what the intended purpose of each rifle cartridge is and how having versatility within a caliber is a good thing for you and the 2A community in general.

    I don’t know about you, but I’m ready to rack the charging handle on my AR platform and squeeze the trigger on this comparison between 308 vs 300 Blackout. Let’s close distance and ENGAGE!

    308 vs 300 Blackout: A Tale of Two 30’s

    As we mentioned earlier, the only similarity between the 308 Winchester and the 300 AAC Blackout is that they both shoot the same .308” diameter bullet.

    Each rifle cartridge was developed for a specific role and each excels at its intended role.

    However, the two rounds could not be more dissimilar, and we will explore the differences below.
    300 AAC Blackout: The Dark Ops Wishlist Given Form
    The development of the 300 AAC Blackout (designated 300 BLK by SAAMI) rifle cartridge began in 2010 when Robert Silvers of the Advanced Armament Corporation (which was later acquired by Remington) was approached by a member of the US Military “dark ops” community.

    The unnamed military customer came to him with a problem that Silvers was eager to solve.

    With the widespread adoption of the 5.56x45mm NATO cartridge (civilian ammo designation: 223 Remington or 223 Rem) for the M4 carbine, US troops were having to use the round for both long range and close quarters combat.

    Overall, some special forces units were unhappy with the stopping power that the 5.56 NATO and the 9mm (used in several SMGs) offered during close quarters combat and they wanted something that had more “oomph”. Something along the lines of the 7.62x39mm Soviet round fired through the AK-47.

    However, there were some other requirements that this customer required as well:
    1. The rounds needed to fit into a standard STANAG AR-pattern magazine and maintain a 30-round ammo capacity
    2. The cartridge face must be the same as 5.56 NATO so a bolt change was not needed
    3. It had to shoot 30 caliber bullets and mimic the ballistic performance of the 7.62x39mm Soviet round
    4. The new rifle cartridge needed to be compatible with short barreled rifles (SBR, barrels under 16”) and be completely functional with a suppressor/silencer
    5. Both supersonic and subsonic varieties of ammo needed to be functional for long range shots as well as close quarters battle, respectively
    However, Silvers was not dismayed, and he returned to AAC to begin work on a new cartridge that would meet all these needs. The search for a host cartridge had begun.

    Attempts to integrate new calibers into the AR platform were nothing new to the shooting community. The adaptation of the 6.8 Remington Special Purpose Cartridge (SPC) and 6.5 Grendel into the AR platform were mildly successful; however, they fell short of the mark in several key areas.

    The 6.8 SPC and the 6.5 Grendel have a larger case head than the 5.56 NATO cartridge, so a new bolt was required for the host carbine.

    Secondly, although both cartridges could be loaded into a standard capacity AR-15 magazine, they could not be loaded to 30 rounds because of the increased case size.

    Colt Firearms and other manufacturers had been unsuccessful in adapting a 30-caliber cartridge to the M4 carbine. Complicating matters, the M4 cannot be easily modified to simply shoot 7.62x39 Soviet either as the severe case angle causes multiple chambering issues using a standard M4 magazine.

    As Silvers continued his hunt to find a proper host cartridge for his new round, he started looking at different wildcat cartridges in the shooting community.

    The 300 Whisper was probably the best wildcat cartridge that Silvers encountered, and it eventually became the host for the 300 BLK. That being said, the 300 Whisper could not simply be adapted to be fired from an AR platform because it did not have standardized loadings with SAAMI (Sporting Arms and Ammunition Manufacturers’ Institute).

    As AAC/Remington was a SAAMI company, it could not load 300 Whisper ammo. Therefore, Silvers took the concepts from the 300 Whisper and modified them to meet their design specifications.

    The new round was called the 300 AAC Blackout (300 BLK) and was approved by SAAMI on January 17, 2011.

    300 BLK Ammo Specs

    Since its approval by SAAMI in 2011, the 300 BLK has exceeded expectations in almost every category.

    With an overall case length of 35mm, the 300 BLK has a case capacity of approximately 19.2 grains. The reduced case length was required to allow it to fit into a standard M4 carbine magazine while being loaded with a longer 30 caliber bullet.

    300 BLK ammo can be broken down into two different bullet weights, 220 grain subsonic and 110 to 125 grain supersonic.

    Supersonic ammo, typically firing a 125 grain bullet, will have a muzzle velocity of approximately 2250 fps and have a muzzle energy of around 1404 ft-lbs. Industry standards list the effective range of the supersonic 125 grain bullet loadings to be 500 yards.

    In contrast, subsonic ammo will fire a 220 grain bullet and have a muzzle velocity of around 1000 fps and a muzzle energy of 488 ft-lbs with an effective range of 200 yards.

    These two popular loadings really illustrate the versatility of 300 BLK ammo. With a simple magazine change, a shooter can switch from supersonic ammunition and long-range engagements to subsonic ammunition for short range combat.

    Furthermore, the 300 BLK was designed specifically to experience a full powder burn when being fired in a 9” short barreled rifle (SBR), preferably with a suppressor/silencer.

    308 Winchester: The Tried-and-True Warhorse

    The 308 Winchester (7.62x51mm NATO designation) has been in service with the US Military for over 60 years and is the quintessential hunting round for whitetail deer to black bear.

    The development of the 308 Winchester began from the needs of the US Military to advance into a new realm of battle rifles similar to the STG-44 and the AK-47.

    In 1952, the U.S. Military started developing a replacement for the long-serving 30-06 Springfield cartridge (military designation: M2 Ball or 7.62x63mm).

    Although the 30-06 Springfield had honorably served through both World Wars and Korea, the US Military wanted to develop a new cartridge that was lighter and more suitable for fully automatic rifle fire.

    With advancements in rifle powder technology and case design in the 1950s, the new 7.62x51mm NATO rifle round was able to achieve nearly identical ballistic performance as the 30-06 Springfield with a shorter cartridge case length and lower overall weight.

    The US Army officially adopted the 7.62x51mm NATO round in 1958 and it has been in service ever since.

    Although the 7.62x51mm NATO cartridge and its parent rifle, the M14, only saw limited frontline use in Vietnam before being replaced by the 5.56 NATO, the military was quick to adapt it to use in sniper operations and in fully automatic machine gun use.

    With a massive effective range out to and beyond 800 yards, it didn’t take long for civilian firearms manufacturers to take notice of the new military round.

    Winchester was the first to adapt the new cartridge to its Model 70 bolt action rifle, renaming the cartridge the 308 Winchester.

    The 308 Winchester quickly rose to be THE long-range high velocity hunting round that had enough muzzle energy to stop a black bear in its tracks.

    Since its acceptance by the hunting and competitive shooting communities, the 308 Winchester has been a staple at deer camps and F Class Shooting Competitions alike.

    308 Winchester Ammo Specs

    308 Winchester ammo is available in a delirium-inducing amount of bullet weights. From 55 grain all the way up to 220 grain weight bullets, you will never lack variety when it comes to selecting the best 308 round for your purpose.

    With a 51 mm overall case length, the 308 Winchester offers a whopping 52 grain case capacity. This translates to a 150 grain bullet loading have a shoulder-bruising 2820 fps muzzle velocity and a muzzle energy of 2648 ft-lbs.

    300 Blackout vs 308 Winchester: The Comparison

    Although these calibers are two completely different rounds with differing modes of service, I wanted to give you a quick rundown of each rifle cartridge to explain the pros and cons.


    In this category, there is simply no contest. The 300 BLK wins by an absolute landslide having approximately 4x less recoil when compared to the 308 Winchester.

    Now I know what you’re thinking, because I’ve thought it too…“Recoil shouldn’t matter, just tough it out and focus on the shooting fundamentals!”

    And I’ll say that on paper, you’re probably right. However, this rarely happens in the field.

    Shoulder fatigue is a real problem when firing for long periods or trying to line up follow-up shots. Once this happens, a shooter will start encountering recoil anticipation, trigger jerk and over-correction; causing their down range accuracy to suffer.

    When it comes to recoil, the 300 Blackout is clearly the better option.


    We’ve produced some absolutely sick ballistics tables for you a little further down in this article, but I wanted to share a few highlights for you here.

    When it comes to ballistics coefficient, the 308 Winchester is the clear winner when comparing to the 300 Blackout supersonic ammunition. With an average BC of around 0.45, the 308 Winchester is clearly the winner as 300 BLK ballistic coefficients typically below 0.4.

    In terms of bullet drop and velocity (fps), the 308 is clearly the winner here as well. But this shouldn’t surprise you too much as the 308 was specifically designed to be effective at longer-range.

    Home Defense

    Both the 308 Win and the 300 BLK will serve you well in any self-defense situation. However, there is one critical thing to consider when discussing close range engagements.

    And that critical issue is: Overpenetration

    The 300 BLK was specifically designed to be shot in a SBR with a suppressor, which makes the 300 Blackout the better choice for indoor, short range engagements.

    Furthermore, the 200 to 220 grain subsonic ammo is a partial safeguard against overpenetration as it will begin to lose velocity rapidly when it enters a target.

    Compare this with the 308 Winchester freight train that might end up blasting through 2-3 suburban houses (and potential innocent bystanders) before even blinking an eye.

    Remember, “Every bullet you fire has a lawyer attached to it” as my first shooting instructor was fond of saying. Therefore, we must carefully consider overpenetration when shooting in close quarters for self-defense.

    This makes the 300 BLK the ideal home defense choice with its low recoil (faster follow-up shots), AR platform integration (modularity and light weight), short barrel compatibility, ease of sound suppression, and 30-round magazine capacity.

    Suppressor Integration

    Again, the 300 BLK is the clear winner here as it was specifically designed to be used with a suppressor.

    One of the coolest things I’ve ever seen/heard is a subsonic 300 BLK being fired suppressed. It’s literally “movie gun” quiet.

    You know what I’m talking about right?

    When James Bond whips out his suppressed AR-15 or KRISS Vector and starts blasting away in full auto and all you hear is the sound of the wind…

    Yeah, it doesn’t work like that in real life.

    There are two things which make a bullet loud: the explosion of the powder and the “sonic crack” of the bullet breaking the sound barrier.

    A silencer can greatly reduce the sound of the powder explosion, but if the bullet is supersonic, there will still be a “crack” of the bullet breaking the sound barrier.


    If you’re shooting subsonic ammunition, there is no “crack” because your bullet never broke the sound barrier.

    With this in mind, you can effectively shoot hearing safe with a 300 BLK, a suppressor, and subsonic rounds.

    Long-Range Shooting and Accuracy

    Again, there is no comparison in this category as the 308 Winchester clearly dominates.

    With its massive case capacity, high velocity, lower bullet drop, higher ballistic coefficient, and massive effective range, the 308 dominates the long-range shooting scene when compared to the 300 BLK.

    However, this should not come as a surprise and the 308 Winchester is specifically designed for long-range shooting.

    300 Blackout vs 308 for Hunting

    I wanted to discuss hunting applications as a separate topic as this is one area where there is some controversy in the shooting community.


    Yeah, I know we talked about this already, but it bears repeating here as it is a factor to consider.

    With 4x less recoil, the 300 AAC Blackout is going to be a lot more forgiving when it comes to making follow-up shots and this can be the difference between ethically harvesting an animal and having a wounded animal escape.

    Rifle Availability

    In this category, the 308 is the clear winner as it has been around for over 60 years and has seen wide-spread hunting success.

    Almost every rifle manufacturer will have an offering in 308 Winchester. In comparison, 300 BLK is a relatively new kid on the playground and there are fewer offerings.

    However, many manufacturers are warming up to the 300 Blackout and more rifles are being offered. You can even get a Ruger Mini-14 in 300 BLK now!

    Still, there are going to be hundreds of bolt action and semi-automatic options for 308 Winchester hunting rifles, so 308 gets the nod here.

    Ammo Varieties

    308 Winchester takes this one as well. From the Barnes Varmint Grenade to the Hornady InterLock to a Nosler Partition, there are literally about as many varieties of 308 Winchester ammo as 223 Remington.

    As 300 Blackout has only been around for about 10 years, there are fewer varieties of ammo available on the broader market for hunting.

    Effective Range

    This one can be a little deceptive as it is easy to just say, 308 wins it because it can shoot out past 800 yards. But when you consider that, you need to ask yourself a question:

    Can you ethically take an animal at 800 yards?

    I’m going to wager that a most responsible hunters will not be comfortable taking a shot at a game animal at that range.

    With that in mind, I think it is safe to say that this one is a wash between the two rifle cartridges as most ethical hunting shots will be taken under 400 yards.

    Stopping Power

    This is a category where the 308 Winchester really shines. With a whopping 2648 ft-lbs of muzzle energy, the 308 Winchester clearly has more stopping power than a 300 BLK.

    Does that mean that a 300 Blackout is ineffective as a hunting round? Not at all!

    However, I would say that it would not be ethical to hunt anything larger than a whitetail deer with a 300 BLK as penetration and energy drop off significantly out past 400 yards.

    A Note on 300 AAC Blackout Subsonic Ammo and Hunting

    Reports from the field have shown less than stellar penetration data from the use of subsonic ammunition on medium size game animals, such as feral hogs and whitetail deer.

    It is the recommendation of this writer that only supersonic ammo be used for hunting with 300 BLK on medium sized game animals.

    Subsonic rounds should be sufficient to take down small varmints such as coyotes, groundhogs, etc.

    Continue reading 300 Blackout vs 308 Caliber Comparison: Why Intended Purpose Matters at Ammo.com.
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    \ if your looking for a hunting cartridge in a AR15 platform the
    the 350 legend , 6.8mm spc or 6.5 mm Grendel are all much better options

    keep in mind the 300 blk is and was always designed to be a cartridge whose only real reason for existing was to provide a AR15 compatible cartridge designed to use a SUPRESSOR, and be used at reasonably short ranges on two legged (terrorists) opponents at ranges under 150 yards
    with states like TEXAS making the fabrication of a SUPPRESOR far less of a legal hassle,
    I fully expect sales of the 300 BLK in AR15 kits to get far more popular
    this 300 blk, is not a hunting cartridge or a battle rifle cartridge,
    its designed to be a big improvement over s 9mm pistol cartridge in a suppressed carbine
    think of it as a sub machine gun cartridge, thats been designed for suppressor use,


    300 black-out,
    you might want to think of the 300 black-out as
    a cartridge that was primarily designed for suppressor use


    these plated cast, 220 grain, bullets are designed to use with a suppressor,
    in a 300 black-out, cartridge in an AR15 carbine ,with a suppressor,
    typically a 10"-16" barrel to keep the over all length reasonable.
    they cost only about 20 cents each keep the velocity below 1250-1300 fps.
    faster powders preferred, remember your limited to about 1000 fps max if you are to avoid the sonic crack of the bullet breaking the sound barrier, so pushing a 190grain-220 grain projectile greatly adds penetration, if thus limited in velocity, but a 30 caliber projectile weighting 220 grains requires a fast rifle twist for stabilization,
    the 300 black-out , loaded with the 220 grain bullet,
    has easily more than double the typical 9mm carbines power at 100 yards

    10.5 grains of IMR 4198
    is a common well liked load in a suppressed 300 black-out with a 220 grain bullet

    and use a 7:1-to-9:1 twist rate barrel to maximize accuracy and not have suppressor issues,
    remember you want to have heavy and accurate projectiles leave the suppressor,
    be below the sound barrier,
    this 220 grain plated bullet in a 300 black out,
    far exceeds the typical 9mm sub machine guns power ,
    accuracy, range and penetration,

    with a 220 grain bullet at 1000 fps, making it far more lethal than a 9mm submachine gun cartridge,
    at ranges out to about 150 yards with a suppressor in use,
    and if swapping to a non-suppressor use,
    and about 130-150 grain ammo far more lethal than a 223 rem,
    out to about 350 -400 yards
    Last edited: Jul 12, 2021
  2. rlphvac

    rlphvac reliable source of info

    I haven't cared for the 300 BO from the first time I read about it if you want a 30 caliber get a 30 caliber not a reduced 30 caliber just my opinion I never looked at ballistics loads or really anything about the 300 BO kind of like my opinion of a 380 pistol as half a 9mm that costs more to run for half the performance
  3. Grumpy

    Grumpy The Grumpy Grease Monkey mechanical engineer. Staff Member

    the sole reason the 300 black-out chambering and cartridge exists in my opinion,
    is to maximize performance of a close range suppressed carbine/ used in the basic AR15, platform.
    what your limited to if used suppressed,
    and you want max noise reduction,
    is a projectile that basically can't exceed about 1100 fps,
    or you get an audible CRACK/ :(

    caused by the projectile exceeding the sound barrier,

    and the suppressor on a 300 black-out chambered carbine ,
    can't do anything to eliminate that aspect.
    while its true, a suppressor on a ar 15 carbine with a 14"-16" barrel,
    does reduce the noise the cartridge gasses produce , as the bullet exits,
    and all but eliminate muzzle flash,
    this reduction in noise signature is maximized only if ,
    you used the matching sub sonic ammo,
    what it can do is allow you to push a 220 grain bullet to about 1100 fps thats about 600 ft lbs of energy
    or about what a similar pistol caliber 10mm carbine would allow,
    if your looking to take out a terrorist sentry at 70-120 yards,
    with less chances of alerting his buddies.. the 300 black-out has advantages.

    but the advantage with the 300 black out is that if its loaded with different ammo,
    thats instantly available with a magazine/ ammo change,
    and if that carbine is used UN-SURPRESSED, or with the suppressor still installed,
    you can come close to duplicating the 7.62/39 AK 47 cartridge with about 1400-1600 ft lbs,
    if your willing to live with a noticeable increase, but still less noise than the unsuppressed carbine has, in noise.
    if your not building a suppressed rifle I see no advantage in the 300 chambering
    and keep in mind SUPPRESSORS REDUCE NOISE,
    LIKE IN THE MOVIES.. and yes...

    there's a HUGE difference in the quality and efficiency ,
    in different suppressor designs:rolleyes:

    Last edited: Jul 22, 2021
  4. Grumpy

    Grumpy The Grumpy Grease Monkey mechanical engineer. Staff Member

    a couple other basic ar 15 alternate cartridge options

  5. Grumpy

    Grumpy The Grumpy Grease Monkey mechanical engineer. Staff Member

  6. Grumpy

    Grumpy The Grumpy Grease Monkey mechanical engineer. Staff Member

    heres a couple better quality suppressor videos
    but still not a top quality suppressor
    Last edited: Jul 24, 2021

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