I have always felt that one of the greatest advantages of America’s Black Rifle is modular construction and the .300 Blackout is a popular option for many reasons. It is simple enough to quickly change the upper to a carbine, long-range rifle, or even a different caliber such as the 6.5 or 6.8 caliber. A carbine with a good trigger action may be fitted with a long barrel for competition use. A home defense rifle may become a hunting rifle. While you may change barrels obtaining a complete upper is by far the simplest and cost effective in the long run.
The .300 Blackout is a popular option for many reasons. First, the conversion works and is reliable. The bugs are worked out, and the rifle will feed function and run with .300 BLK ammunition. The .300 BLK uses AR-15 magazines and the standard 5.56mm bolt carrier assembly.
Ammunition is highly developed. The original intent of the .300 BLK was to offer an effective cartridge for use in suppressed weapons. The heavy weight subsonic loads fulfill that mission superbly. Accuracy is a long suit of the .300 BLK. It isn’t unusual for custom grade rifles to deliver sub MOA groups at a long 100 yards. The question, then, is power not accuracy. The .300 BLK is accurate enough for any use. Reliability is confirmed in credible rifles.
As for power the .300 BLK is comparable to the 7.62 x 39mm. Remember, velocity is often expressed in a short-barrel rifle—not the full-length rifle—I am testing. Also due to the extreme aero dynamics of the bullets used the cartridge outperforms the Soviet cartridge at 200 to 300 yards. However, never mind that, the AK-47 isn’t accurate for long-range use and neither are most 7.62 x 39mm AR-15 uppers. The .300 BLK is NOT an alternative to the .308; these are completely different missions.
The .300 BLK is a pretty exciting option for use in suppressed rifles with short barrels. I do not play with such items, but have friends that do and find them a fascinating study. The .300 BLK is a credible option for entry use and for dispatching lights and guard dogs. The .300 BLK should be the equal of the 5.56mm at short range as far as wound ballistics and considerably superior to the 5.7mm, .30 caliber carbine, 9mm SMG, and the like. However, some of us will use a standard 16-inch barrel conversion for the .300 BLK.
Ruger offers a seldom seen Mini 14 variant in .300 BLK as well. My perception of the rifle at first is that this is a specialized caliber. It is ideal for the use it is intended but a far as hunting, I think that a very narrow spectrum of performance, perhaps as a hog gun, is where we are at with the rifle. With this in mind, I decided to test a number of loads using the Rock River upper with the .300 BLK. The scope is a TruGlo illuminated reticle version.
Gorilla Ammunition
This company was founded on the .300 Blackout and offers a number of first class loads. The load I tested was the 125-grain Sierra MatchKing. This is a bullet with excellent accuracy potential. We are dealing with a bullet with much better sectional density than the .30-30 WCF with its 150-grain bullet at 2200 fps so the 125-grain Sierra just may make a comparable deer load given good shot placement. It is lighter than what I like for deer, preferring the .308, but something must be said for low recoil and excellent accuracy. This load breaks 2150 fps average.
Hornady American Gunner 125-Grain JHP
At 2200 fps, this load remains controllable. The new American Gunner .300 BLK is available in 50 round boxes which aids in inexpensive (relatively—expense is relative with the .300 BLK) practice. Accuracy is good and the powder burn is clean. Hornady’s quality is evident. Hornady also offers a 110-grain load I was unable to test at this time.
Fiocchi Rifle Shooting Dynamics
This is a relatively heavy bullet at 150 grains. Velocity is 1950 fps. Of the loads tested, this load seemed to give the lowest recoil and also burned clean. Accuracy was excellent, something we were getting used to with the .300 Blackout. This is a good accurate affordable burner load with much to recommend.
PNW Arms
I have used the Sierra MATCHKING 220-grain bullet in the past in the .30-06 rifle with excellent results. These old heavyweights can be quite accurate. The combination looks odd in the short .300 BLK case, but shoots as well as anything at moderate range. At 1050 fps from the 16-inch barrel, this load would be ideal for a suppressed rifle with a short barrel. Velocity would probably drop to about 950 fps in a SBR.
The drop was greater than the other bullet weights, but for the intended purpose, personal defense, this is a credible choice. PNW also offers a 147-grain bullet load. This is the same bullet weight used in bulk .308 loads and a good choice for economical practice. Velocity is around 1950 fps on average. This loading also gave a clean powder burn, which seems to be a hallmark of the .300 BLK.
SIG Sauer 120-Grain All Copper HP
SIG may have introduced the best hunting load so far in this interesting caliber. With an all copper HP at 2,250 fps from a 16-inch barrel this loading offers excellent accuracy and predicted effect on target. SIG also offers affordable FMJ training loads.
HPR
HPR offers a 220-grain subsonic, 110-grain practice load, and 110-grain hunting load. Ballistic testing with the 110-grain load is impressive. The all copper bullet expands to .50 at a solid 2100 fps. This is an outstanding load that burns clean—a big plus that HPR ammunition always demonstrates.
After firing a modest amount of .300 BLK ammunition, I find a clean burning accurate cartridge with interesting capabilities. It is something of a wonder cartridge with excellent accuracy and low recoil. One thing is certain the loads are first class examples of the maker’s art.
Are you a .300 BLK fan? What is your favorite .300 BLK loading? Share it in the comment section.
[bob]
I wanted an AR platform that I could load a variety of .30 bullet and the 300 BLK is a cheap cartridge conversion with a lot of versatility. I prefer the 125 grain Sierra bullets but have loaded a lot of cheaper 130 grain bullets with good success. I found some 145 gr surplus euro mil surplus and made a great load out of that. I even loaded some USGI AP rounds as an experiment and was able to penetrate 1/4″ cold steel at 25 meters, try that with 7.62×39! My AR pistol in 300 BLK with a 12″ barrel makes a great poor man’s SBR and is effective and fun!
The 45acp is superior to the subsonic 300 BO rounds, too bad none of the manufacturers will produce 45acp uppers for less than the whole rifle in 5.56.
Maybe on your planet but not on mine..
If you look at gel tests of both rounds, the .45 ACP 230gr +P loads do look like they cause more tissue damage than subsonic .300 BLK rounds. Even comparing Lehigh Defense Max Expansion Subsonic .300 BLK out of an SBR vs. .45 ACP Ranger T 230gr +P out of a 3.3 inch barrel XD-S pistol the .45 has slightly larger penetration and a consistently larger wound travel over it’s entire penetration depth, which penetrates 13″ at an impact velocity of 858 fps. Put that in a carbine and the performance would likely improve.
.45 ACP Ranger T 230gr +P: https://www.youtube.com/watch?v=nwcTEtEmiZo
.300 blk Subsonic: https://www.youtube.com/watch?v=JDym4GXrPRw
Ammunition types become very popular for various reasons; used by the US military (30-06, .308 Win, .223/5.56mm, 45ACP, 9mm Luger), Undisputed performers (7mm REM MAG, 300 WIN MAG just to name a few). And then there are the others, the children of outstanding marketing. The most famous of these has to be the .270 WIN. Yes, it a pretty good round, but there are many that are better, but only the .270 became the absolute darling of the press when is was introduced. This is how the .300 Blackout became great. Freedom Group bought Advanced Armament Corp. (AAC) and the 300 AAC came with it, it was rebranded the 300 Blackout, and they promoted this marginal (at best) round like nothing I have ever seen before. Every gun writer in the world wrote about it like it was the greatest thing since the invention of smokeless powder, every gun magazine put it on the front cover, and, low and behold, the same publications were all stuffed to the gills with paid advertising for the 300 Blackout. It’s the ultimate Kool-Aid round…and it dangerous. I have seen several ARs that were blown when a 300 Blackout round is inadvertently loaded into a .5.56 chamber. Unlike other, non-wildcat, AR-15 alternative chamberings, nothing stops the 300 Blackout from loading in a 5.56/223 chamber except the projectile itself. With the right combination of a light crimp (reload usually) and a strong buffer spring (maybe a tap or two on the forward assist), it fits just fine. If you own both 5.56 and 300 Blackout, be very careful.
I’ve have used most of the discussed rounds, however, I cast 220gr and make powder coated BTHP boolits loaded for subsonic and supersonic using 16″ carbine and 10.5 to 7 inch AR pistol barrels in 300 BLK. The carbine loads get up to 1550 fps muzzle. So with that velocity and grain, it is good for not only hog but deer and self defense. This broadens the application window and increases overall single round utility that you can make for about 7.5 cents apiece. Best use I have found for 223 brass is chopping and reforming into 300 BLK.
I have all 3 calibers from above and I also reload all 3. I think from my point of view the 300 BLK is a good round. While it doesn’t compare to the .308 I think its better for all around use than the .223. I like the 300 Blk with either 125 or 150 gain bullets and of course not sub-sonic for me as I don’t have a suppressor. I also like the fact that the brass is easy to come by as I make mine from .223 cases.
The 300 Blackout is a credible performer but I like the 308 better.
A very desperate attempt to supplant the 7.62 Russian within the American
Gun Culture for financial gain by US Gun Manufacturer’s “targeted at the Black Rifle Fan Boys. From a practical view point, the Blackout answers a question that nobody is asking.
Whatever the 300 BK can do, the Russian can do better and cheaper.
Yes the Russian does do better, running with a 8″ barrels and subsonic ammo….they are far superior to the 300BLK if your goal is to not have it cycle or group worth a damn in this configuration.
I find this response interesting. I shoot USPSA and 3-Gun regularly with SF veterans. Many of them and people like them, such as notable SF vets/trainers such as Kyle Lamb and Travis Haley, publicly say they don’t see any issue with 5.56 as a warfighting round. It’s been effective when they’ve used it many times for serious purposes. Now with M855A1 and similar improved issue munitions such as “brown tip” (Barnes TSX 70-grain), is it still an issue? For civilian use, why isn’t Hornady TAP or Speer Gold Dot sufficient enough?
It makes me think of 6.8 SPC, which about a decade ago was going to “replace” 5.56 NATO, first with SOCOM and then probably everybody else. Where is that round now? What did DEVGRU bring with them on arguably the most critical kill mission ever when they dropped in on a residential compound in Pakistan 3 years ago for what certainly was going to be CQB engagements? SBR 5.56s and MP7s, the latter of which use the “puny” 4.6×30 cartridge.
So some JSOC groups have a specialized use for .300 BLK, just like they did a decade ago for 6.8 SPC. I’ll agree with a previous poster that I’m all for innovation in cartridges and arms. However, most people here are espousing the superiority of the .300 BLK as a cartridge for warfighting and self-defense. I’d argue that for the civilian interested in that type of scenario, they’d be better off using the money spent on a .300 BLK platform and ammo (either reloaded or commercial), on 5.56 ammo (with premium defensive ammo if M193 terminal ballistics are that disappointing) and training. Take some serious carbine classes, then practice, practice, practice. Compete in 3-gun, 2-gun or carbine matches and hone skills so that you can shoot as well as those who do it for a living, and I would wager that a properly prepared 5.56 wouldn’t be “too little gun” for any practical scenario.
If you’re into niche collecting, then ignore my points and spend your money to your hearts content. I’ve done that with .50 Beowulf and loved every minute of it.
So many other choices that are far better than the .300 BO. Been seeing to many exploded .556 lately from those who also own the .300 BO and accidentally chambered a .300 BO round in their .556 and blew their nice black rifle to pieces.
I don’t see how someone that puts the wrong caliber round in their rifle is any indication of the performance of a round. Does that mean that sig .357 sucks because someone tried to shoot a 40 cal out of it??
That is why you mark the back of the charging handle with the caliber so it is looking right at you before you pull the trigger
300BLK is one of my favorite loads. PNW 147 FMJ at the range will run pretty much all day w/o issue. Barnes Vortex for home defense can’t be beat. Sig Sauer Elite ammo runs super nice through my “pistols”. Reloading is a breeze with a very large selection of powder and projectile combinations. 300BLK is flat out one of the most versatile cartridges around.
I purchased an AR system last winter, this included a 5.56 upper and a 300 BO upper. I could have saved $130 by only getting one bolt carrier, but I wanted easy interchangeability. I, too, found BO ammo to be a bit pricey, so I bought 1000 rounds of 5.56 once fired brass and a small cutter from Harbor Freight a set of dies and made my own 300 BO cases. This brought ammo prices down quickly. I load 150 gr BT bullets. The rifle handles like a dream, very low recoil, muzzle blast is not as loud as some rifles of comparable caliber that I’ve shot. I’m not a great shot, but accuracy if good. Whenever I see a good price on factory ammo in either 5.56 or 300 BO I get some more. But I really like the idea of pulling out two pins and removing my 300 BO upper and replacing it with my 5.56 upper. Total time needed is about 1-minute.
I have a 3x9x40 on the 300 upper and a red dot sight on the 5.56. It’s illegal to hunt deer with a 22 caliber round, but the 300 BO makes it a legal hunting rifle.
Sorry, but my next AR build will be the 7.62 X 39MM variety. It`s a bigger round, more plentiful and far cheaper to shoot. 300 Blackout is not economical at all.
600 yards and serious lethality. Obviously I don’t know what weight bullet you are using, but from the .300BlkTalk.com website administrator:
16 inch 300 AAC BLACKOUT 125 grain at 2220 fps has:
100 inches drop at 440 meters (481 yards)
41 inches drift at 484 meters (529.3 yards)
291 ft/lbs of energy at 700 meters. (765 yards)
I have no idea why he chose that last distance for the energy calculation, the energy would be something more @ 481 yards.
From the above source “Using M4 military hit-probability standards, the max effective range of 300 AAC Blackout from a 16 inch barrel is 460 meters.”
The US Army’s definition of maximum effective range: “The distance from a weapon system at which a 50 percent probability of target hit is expected, or the tracer burnout range.” (FM 101-5-1). Remaining energy has no application in the military calculation of maximum effective range.
So I guess that is 548 meters with serious lethality if your moderate quality optic can be dialed in to consistently hit at that distance, always dependent on wind, mirage and light conditions at the time of taking the shot.
The greatest thing about the .300 blk is that you don’t have to buy one if you so choose. I happen to love mine. It’s SMG small, impressively quiet, has formidable terminal ballistics even when suppressed, and accuracy that brings a smile with every trigger pull. Reloading brings the cost per Round way down into .223 territory. That being said, I also love my 5.56 & 7.62. Each one has its own unique “sweet spot” I support the innovation and development of new rounds and platforms. If it were not for free and forward thinking we would be taking muskets to the range on weekends…, oh wait, I do that sometimes too.
The 300 Blackout sounds great for a suppressed weapon to shoot lights out guards and their dogs at Stalag 13 but I do not think I will have to save colonel Hogan from Colonel Klink anytime in the near or far future. The ammo is expensive and rare compared to 556 or 308. If I owned this gun I would cringe every time I had to buy ammo knowing I will never use this gun for its intended purpose when I could pay less for easy to get bulk ammo
It’s obvious the only place you must shop for ammo is Walmart because 300 BO ammo can be found everywhere. It is abundant and there is a wide variety available as the author points out. And the price per round keeps dropping but of course it will never get to the bulk ammo rates that you find for the .308 / .556. Show me any other round that does.
For a pistol arrangement, just say for a trunk or backpack get you home gun, would you be better off with a 9″ 5.56, 9mm Glock or 300 BO supersonic?
That 300 would also be 9″
Well this is the dumbest and most pointless article I have ever seen on this usually informational and entertaining site. “The .300 Blackout is a popular option for many reasons. First, the conversion works… …the rifle will feed function and run with .300 BLK ammunition…” Well, yeah, I hope so. Gee, what a great selling point!!!! “I do not play with such items, but have friends that do and find them a fascinating study.” ” The .300 BLK should be the equal of the 5.56mm at short range as far as wound ballistics and considerably superior to the 5.7mm, .30 caliber carbine, 9mm SMG, and the like.” Oh yeah? Why? How? Totally different cartridge, totally different velocity. Wow. Here’s your sign. Wow.
And then there’s those who need to justify fad purchases
I think the 300 is an orphan looking for a home, it’s not a 7.63×39 nor is it a 30-30, yea it shoots thru an AR platform but so does so many other rounds, OK, it works great with a can, so what, so does my 223 and 308 and any other round that runs on an AR platform or any other for that matter, hell take your 30-30 and thread it for a can, cheaper and better in the long run.
Sorry, I know for you folks that have the need to park the latest thing in your gun safe this is a “Super Wow!” but not for me and I suspect most of us.
One can easily tell that you have not spent any real time behind a .300 BO. It’s a very accurate and hard hitting round when using supersonic rounds. It was never intended to be a long range round, it was meant to be a compact round that is harder hitting than the 5.56 and used for close quarters combat. And toting the same amount of 300 BO as 5.56 does not take up any more space and not that much more weight, try that with the .308.
Don’s answer his the nail on the head. I have real world CQB combat experience and I would definitely traded my 5.56mm loads (there are plenty of examples of the inadequacy of the 5.56 to stop threats in and at CQB ranges)some hard hitting .300 BLKOUT. Also, for cqb the weight of the AR-15 platform compared to the AR10 is much more practical for reflexive firing and maneuverability. Because of the popularity of the 308 there is an almost endless amount of projectile combinations to try. Also, it is a great round for running supressed.
No it was actually made to make money for the manufacturer! Sorry to bust any bubbles.
Lots of great rifles are available direct from manufacturers such as SIG, Robinson Armament, and other non-AR builders in .300, but also look at the single-shot from CVA, and the top-break pistol, that comes threaded for a suppressor. And affordable bulk range ammo is available.
300 is a disappointment. 7.62×39 outperforms it in a great barrel. I shoot 7.62×39 to 400 yards with accuracy. Beyond that, the Grendel takes over. Yes, there are better choices than the 300, for far less $.
You clearly haven’t fired a 300 blackout
Sorry. Gonna wave the BS flag on that post.
.300 BlackOut offers superb balitics at serious lethality to 600yrd with moderate quality optics.
Nick i agree. I also have a scorpion and a MPX and the 300 is much more quiet. With my Bowers can and my load listed with my Encore it is as silent as my 22 rifles suppressed…
I’m a fan of the round and I’d like to point out a few areas where it really shines, to illuninate nay-Sayers.
1: it excels in short barrels. The powder in the 300 AAC is supposed to be completely burnt within 8″, allowing for ultra short carbines without the massive muzzle blast of other common calibers.
2: it offers a plethora of bullet weights for the AR in a single cartridge. You can fire anything from 110grn screamers up to 220 (and some go higher) subsonics. The native ability to go subsonic is a relative rarity in the AR, since most don’t handle it well, but 300AAC barrels have the appropriate twist rates to stabilize the long, slow, heavy bullets.
3: Suppressed. If you own a 7.62 suppressor, why don’t you have a 300AAC? They are almost scary quiet with subsonics. I also have a Scorpion Evo 9mm. Even running both with subs, suppressed, the 300AAC wins hands down on volume, and is firing a 208grn bullet compared to 147 in the 9mm.
Nick
Thanks for your input. My primary intent was to make the reader aware of the variety of loads available in this caliber. As you mentioned it is a great cartridge, ideal for a very small niche but certainly worthwhile.
The more powerful 6.5 and .308 simply are not as well suited to suppressed use.
Best,
RKC
I can tell from the other comments that they have not shot this round suppressed. I load and shoot this round suppressed in two bolt guns and one single shot rifle. In my expierence shooting subsonic with this caliber it is far superior then the 308 and more accurate. With less case capacity it is much easier to find a consistant load then the 308 or any other caliber.. Sub gun rounds, 9mm, 45 acp ecx can not be put in the same catagory with the blackout round. I regularly shoot this round out to 500 yards with great success suppressed and subsonic and it will out preform the 308 with subsonic ammo all the time. Supersonic the 308 is king. My favorite load for my encore and Bagara barrel is 5.5 grains of trailboss powder with a 150 grain montana extreme bullet. .500 to .600 at 100 yards is the norm. Running at 960fps it is the quitest load i have found and is good out to 200 yards.
My two bolt rifles i shoot 220hpbt sierras with H110 powder 9.9grains at 1065fps. I do not shoot supersonic rounds in my guns i prefer my 308 for that.
Accurate? No. Overblown hype? Yes. 6.8 SPC is the best choice for the M4 size system. 6.5 Grendel is not the best choice for the short barrel, but it is much better than the blackout and 5.56. Long range, the 6.5 is even better than 7.62 x 51
I don’t see any logic in this caliber.
I’m happy with my 2 AK’s, my AR-15, and my AR-10. If I ever get an urge to get something exciting to add to my collection, it would probably be a .50 Beowulf AR, or a Zastava M77 7.62×51.
@ ss1.
Bottom Line, is Range:
1. .308Win (.308/7.8×51.18mmR) Flat Trajectory Ranges is ~548.64-meters
2. 7.62×51 Nato (.308/7.82×51.2mmR) is ~600.89-meters
3. .300Blk (.308/7.8×34.7mmR) is ~459.94-meters.
A Bunch of “Knuckleheads” in the Woods Shooting at Dear from a Distance, with the Possibility of Killing Each Other…
As soon as you said
“However, never mind that, the AK-47 isn’t accurate for long-range use”
I questioned you’re expertise and opinion, which I done in many of your articles.
And just how accurate have you found the AK 47 rifle to be at 200 and 300 yards range?
I am always interesting in practical experience rather than groups fired with a type writer.
I think most of the experienced shooters understand just how inaccurate the AK 47 rifle actually is.
Isnt life great. I like the ak too but if you want to keep it grouping in a 10inch circle or less 250 yards is tops….
And here you go: Travis Haley making consistent hits out at 500 meters with a 1951-built AK with original parts. Then using a Rifle Dynamics build to make consistent hits at 600+ meters.
https://www.youtube.com/watch?v=hqyegxlLnJE
Since it’s so similar to 7.62X39 why is it like 3X more expensive?
Disagree! Best is 6.5mm Grendel !
Far too expensive per round compared to existing rifle rounds, and with subsonic the ballistic performance is a yawn. You can get quiet and cheap with suppressed pistol caliber carbines for a fraction of the investment of .300 BLK. I have a .50 Beowulf which is much more capable and fun as an expansion of the AR platform. To each their own, but IMHO .300 BLK is a fad that doesn’t have enough advantages to justify the investment.
Adopted by U.S. military, won’t be a fad. Outranges the 7.62×39 russian. More punch than SMG rounds, accurate as hell and fun to shoot. I load my own for cheap cost compared to commercial ammo. Good flexibility. Do the math; a 150gr. .300blk has more energy than the 62 gr. 5.56mm.
These comments are getting too specific. Not everyone loads their own, Not everyone makes their own guns for Pete’s Sake. Concede the generalizations, that off the shelf; the 300 vs 7.62 X39 performance, does not justify the $ cost per round!
The 30-03 only lasted 3 years.
The .300BO doesn’t add up to me. The 7.62×39 can be both a cheap plinker or a 200yd deer gun. And at the end of the day that is all the 6.8 and .300BO is. Dropping a 300# buck isn’t the same as punching holes in paper.
I have a Ruger GSR in 7.62 NATO/.308 Winchester. Granted a Bolt Action Rifle. As far as accuracy and to only one firearm….as the rifle Col. Cooper described to build……I have no issues with it.
The 6.5 and the the 6.8 are definite improvements over the 5.56 NATO/.223 Remington.
The advantages offered of those two calibers Definitely are far superior to the .300 BLK. The .300 BLk ballistics are pretty much equivalent to the 7.62 x 39mm and the .30.30 Winchester.
Is the .300 BLK better than the other two calibers? PERHAPS if one is using the suppressed loads and more or less intermediate range…
There is no comparison in longer ranges…….The data is quite clear.
Does that mean the .300 BLK is a bad round or a useless round….??? NO NOT AT ALL. As far as suppressed rounds I don’t think IN GENERAL there is any comparison to I or it’s capabilities….. IF NOT, while using a suppressed round……..why not go ahead and use the 7.62 NATO /.308 Winchester?
well put. None of the rounds you mentioned are bad rounds and each has their own advantage. Each caliber will have a configuration that will favor one or the other. 300 blk is great for running suppressed and short barrels at relatively closer ranges. 6.8 works very well in most barrel lengths and pushes out to medium distances. 6.5 I’ve only ever seen in longer barrels, over 20 in, but extend out to long range. Ballistics wise they are all an improvement on the 556 and at close range they will all perform in the same general category with the exception being 7.62 nato. Its a full rifle caliber round and is superior to any intermediate caliber. Sorry Grendel fans, you like to claim that the 6.5 grendel is better than 308 but you compare your Lapua rounds to M80 ball ammo. Look at ammo that is actually designed for long range and the grendel looses its luster and far more ammo choices in 308. Every caliber has its advantages and its own disadvantages just like the .50 Beowulf is devastating up close but you lose out on ammo capacity, availability, and range.
The rule of thumb in reloading the fuller the case is the consistancy of velocity is better and this is definatly true with the 300 over the 308 with subsonic loads. The case capacity of the 308 is so much more than the 300 subsonic loads will never be as consistant as the 300. I use a ohler chrono in all my subsonic load testing and have found out that this is exactly the case. The 300 will be more consistant which equates to a more accurate subsonic round with using less powder less muzzle flash and less sound signature. When a suppresser is used the 300 is more quiter. The ammo manufactures no this also. Just think have you ever seen a commercial made 308 subsonic round that you can buy over the counter. I have never seen one…