300 Blackout - A Tale of Ten Loads

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300 Blackout - A Tale of Ten Loads

Post by Regaj » Thu Nov 12, 2020 10:32 am

You watch the videos with a kind of morbid fascination. A city at night, lit by splashes of light. Shouts and screams and movement and anger and chaos. Fire around the edges.

The Kid is unwise is so many ways. And yet it’s undeniable that when the matter is finally, irrevocably joined, he and his weapon rule the darkness, imposing a sudden, implacable justice upon the mob that sought to devour him.

Those of us who routinely carry weapons against the evil of this world inevitably look to the pistol. A weapon compelling because of its size. It’s small enough and portable enough that the burden of carrying it is judged acceptable.

Alas, its virtues end there. Gunfights involving it are usually fraught affairs, challenged first by the difficulty in getting our bullet to go where we want. And then, if we’re able to achieve that, having that bullet persuade the bad guy to change his behavior. Those challenges together mean a tall order. Like a batter at the plate, they usually fail more than they succeed.

Rifles? Well, they’re long and they’re unwieldy. They’re usually heavy. And they require both hands to operate effectively. Frankly, unless you’re walking in the woods, or in an environment where you expect to be shot at, carrying one is a pain in the ass.

But when the shit hits the fan and daylight turns to dark, when all your chips have been pushed to the center, the rifle brings a profound advantage. It solves most of those two problems that burden the pistol. Like Robert Redford striding to the plate, “Wonderboy” in his hands, the rifle suddenly changes everything.

Come now the PDW, the “personal defense weapon.” A weapon that strives to split the difference. A weapon that seeks to give us some of that portability that defines the pistol and lets it disappear into the everydayness of our lives. And yet one that brings an actual rifle round to bear for when things go sideways.

The 300 Blackout lives at the center of that. A purpose-built round designed for small rifles and short barrels. Other calibers have tried, but mostly have been exercises in expediency over efficacy. Ballistics is a hard mistress.

As usual, I’m late to the party. I cringe when I think of how much ammo I could have bought, and the prices I could have paid for it, had I done all this a year ago.

But better late than never, right? The Daniel Defense DDM4 PDW showed up a few weeks ago. And I don’t know that I’ve ever been smitten, so fast.

When I received the email from the boys in Georgia that my DDM4 PDW had shipped, I had precisely zero rounds of 300 Blackout in the house. Had never even fired the caliber. So began a mad scurry to try and scrape together at least a minimal inventory of factory loads. As you might imagine, that ended up being something of a potpouri. A potpouri I paid through the nose for.

I have not yet performed any rigorous accuracy testing. My 5.56 AR’s wear ACOGs. And my 7.62 battle rifles are topped with high-magnification variable scopes. When the DDM4 PDW arrived I slapped on a Vortex Strikefire II – the only red dot optic I had in the house. A Trijicon MRO in a QD mount will be arriving shortly to replace that. Long story, short… I like magnified optics for any real accuracy work. Once the MRO and its QD mount is here I’ll be able to pop that off and throw a scope on to test for accuracy. In the meantime, the Vortex red dot has been adequate for chronographing loads and figuring out, in general, what is what.

I’ve dispensed with most of the fascinating data that comes from chronographing ammunition. Things like shot-to-shot muzzle velocity, extreme spread, velocity decay, and kinetic energy can give great insight into a round’s performance. But the numbers can get busy after a bit. So I’ve narrowed things down to just three pieces of information: claimed box speed, if the manufacturer listed it; actual muzzle velocity; and standard deviation. Averaged across five-shot strings, with temps within five degrees of 70F.

Muzzle velocity and standard deviation, in particular, tell us a great deal about a round, strongly suggesting both what terminal effects we can expect and how accurate the load is likely to be.

My DDM4 PDW checks in with a 7” barrel. Those of you with shorter or longer barrels will have to adjust accordingly.

We’ll start with some good news… the Barnes 110gr., load came to the party with some serious cred to uphold. I’m happy to report that it measured up, registering both good speed – notably, the only load clocking north of 2,000 fps, albeit barely – as well as good SD. Its terminal effects are reputed to be excellent. And because of all that it’s quickly become my go-to supersonic carry load. It’s what I will zero my optic to, and will be the point-of-impact reference for everything else.

Team Never Quit is at least loosely associated with Marcus Luttrell of Lone Survivor fame. I’d like to like their 125gr., load for that reason, if nothing else. Alas, it came in with marginal speed and a marginal SD. It’s good for plinking, but little else.

Winchester and Remington are both storied names, of course. For many of us, there’s an assumption of a certain quality attached to their ammo. Here, it’s a coin flip. The Winchester 125gr., load made good speed, but with a pretty awful SD. It’s plinking ammo. The Remington 130gr., HTP load, on the other hand, with the Barnes bullet, brought decent speed with an excellent SD. It would be my second choice for a supersonic self defense load. And probably my first choice for whitetail deer, were I inclined to hunt large game with the 300 Blackout.

Freedom Munitions and Gorilla – two brands I had never shot before - brought the three middleweight offerings. The 147gr., Freedom Munitions load was uninspiring, exhibiting good speed but with a moderate SD. Plinking ammo. The Gorilla 147gr., offering, on the other hand, gave slightly better speed, but also with an excellent SD. Between the two 147gr., loads, it’s clearly the better choice. It should make good target ammo. And if I couldn’t get Barnes 110gr., or Remington 130gr., HTP I’d load up a magazine with this stuff and not feel terribly undergunned.

If the 147gr., Freedom Munitions load was slightly meh, their 168gr., HPBT Match round was anything but. Good speed. Excellent SD. And a load, like the Remington 130gr., HTP, I’d consider as a second-tier self defense load. If you’re debating between the two Freedom Munitions loads, their 168gr., offering is a much better round.

Finally, three subsonic loads bring up the caboose. Subsonics matter in the 300 Blackout world, of course, because the caliber was designed with short barrels and suppressors in mind. Want the quietest close-quarter, anti-personnel round possible, while still retaining a reasonable degree of terminal effectiveness? A suppressed 300 Blackout, firing subsonic ammunition, is your answer.


The Corbon 220gr., load was the first subsonic I shot. You know how when you trigger a shot and know instantly something is amiss?

Yeah. You feel it in your shoulder and at your ears and, in my case, in the chronograph display staring back at me.

Corbon says their round makes 1040 fps. They don’t specify what barrel length that’s from, but most manufacturers spec 16” for the 300 Blackout, so we’ll assume that. So, yeah, we would expect a pretty good reduction when we light off their load through a 7” barrel.

But, crikey… 652 fps! There wasn’t even enough energy to cycle the gun and feed the next round. I was stunned.

Back inside, I quickly confirmed that all five boxes I had received were from the same lot. I drafted a nice, little message and sent that off to Corbin, giving them that information, my results, and asking if they had any comment. Crickets.

A few days later, my order of 200gr., Sellier & Bellot showed up. The small, green box has kind of an old-school look to it. Right on the front it says “tactical ammunition.” They spec their load both in a 16” barrel (1060 fps) and 10” barrel (960 fps) – which is a nice tip-of-the-hat to real world usage. And, alone among the ten loads I tested, theirs came with sealed primers. Even their name has a kind of gravitas to it. I really wanted to like it.

Alas, the bench doesn’t lie. At 760 fps this load was notably better than the Corbon shit, but still well under what I’d consider minimum necessary velocity for anything going into harm’s way. SD was good, though. So if you want a really soft-shooting round that maybe will cycle your gun, while grouping pretty well, this one might be the ticket.

With two up and two down, my opinion of subsonic 300 Blackout wasn’t real high. Especially after the rather mediocre performance its 125gr., sibling had put in, I didn’t hold out much hope when the Winchester 200gr., subsonic load showed up. So it was a pleasant surprise when it proved itself to be head and shoulders above the Corbin and Sellier & Bellot loads. At 913 fps it clocked good – which is to say, expected – speed for a subsonic load in a short barrel. And it displayed a good SD. Finally, we have a subsonic load capable of serious work!

Happy as I was to finally have a good subsonic offering, I still remained curious about the dismal performance put in by the Corbin load, and the not-quite-as-bad-but-still-sucky numbers put up by the Sellier & Bellot. So I reprised all three subsonic loads, at the same time, with all shots happening within fifteen minutes of each other.

Both the Winchester and Sellier & Bellot loads confirmed their previous performance, with very similar velocity and SD numbers.

The Corbin… geez, just when you think it can’t get any worse – 577 fps (versus 652 fps in the first series) and a SD of 38.36 (versus 25.78 the first time). All from the same frickin box of ammo! Far and away the most inconsistent factory ammunition I have ever come across.

One last thing and I’ll wrap this up. Discreet Ballistics specializes in subsonic ammo. Among other things, they ask you to specify your barrel length and twist rate when ordering – which suggests they are using different powders and/or different charges for those different barrel lengths. That’s something a handloader would do. But something almost never seen in the commercial world. I hope it bodes well for their offering. I’ll let you know when my order is fulfilled in a few weeks.

It’s been a very long time since I’ve explored a new caliber. It’s kinda like that first dance with that pretty girl you had your eye on, back in the day. Much to explore. Much to hope for. And much to learn.




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Re: 300 Blackout - A Tale of Ten Loads - Part 2

Post by Regaj » Thu Nov 12, 2020 10:39 am

A few updates to the story here.

First, Corbon did, indeed, replace the hundred rounds of 220gr. Subsonic ammo that performed so miserably in my original post. Just about exactly a month after I contacted their customer service department, their VP of Operations emailed me, indicating that the particular lot of ammo I had was being recalled. A couple of weeks after that I had fresh ammo in hand.

The replacement ammo came in a different box – blue and white, versus the black and white box that held the original ammo. More importantly, the new ammo performed world’s better than did the original, defective lot:

Corbon’s Claimed Box Speed: 1040 fps
Actual Speed: 904 fps (versus 652 fps and 577 fps in the defective lot)
Standard Deviation: 20.40 (versus 25.78 and 38.36 in the defective lot)

That was out of the 7” barrel in my DDM4 PDW. Out of a 16” barrel (of which more in a moment) the new Corbon ammo measured:

Actual Speed: 1071 fps
Standard Deviation: 40.11

The standard deviation in the replacement ammo is certainly nothing to write home about. But the expected velocity is there. And my initial testing shows that accuracy is good in spite of the rather mediocre SD figures. I’m calling this ammo good.

Having said that, I do find it very concerning that Corbon somehow allowed that defective – and very unsafe - ammo to escape into the wild in the first place. Whatever quality control measures that should have prevented such a flagrant error… clearly failed.

It’s also troubling that at no point have I been contacted by the online retailer from whom I purchased that original, defective lot. That retailer would have no way of knowing, of course, that I was having a back-channel discussion with Corbon’s VP of Operations, and that I was, personally, being squared away via those discussions. It begs the question of how, exactly, an ammunition “recall” is supposed to work.

Having a chronograph is more, apparently, than just about curiosity.

The second update is that, having shot all these factory loads and amassed a tidy bit of brass, I turned towards my handloading bench. For legal reasons I’ll always use factory loads in any weapon I expect might go into harm’s way. But for the whole panapoly of range, practice, and plinking ammo that consumes most of our shooting time, I prefer to use handloads. It’s cheaper. It’s more accurate. And I can tailor it however I want.

My handloading goals were modest… simple, reliable practice ammo. Accuracy wasn’t a huge consideration, so the brass from all ten factory loads went into the same coffee can.

But as I began cranking the press I quickly discovered that some of the brass required very heavy force. Now the 300 Blackout is a quite small cartridge. Short of trying to run an unlubed case up into the die, there was simply no good explanation for needing such excessive force. It was an unusual enough situation that, after sizing, I kept those “hard” cases segregated from the others. When I was done, it turned out that all the difficult brass had an X-TREME headstamp. That’s the brass that Freedom Munitions uses.

This is about factory ammo and so I won’t belabor the minutae of handloading rabbit holes one can crawl down. Suffice it to say that I measured case weights and case volumes (using water) for all ten of those factory cartridges.

The good news is that nearly all those different headstamps were within spitting distance of each other. Empty case weights between 87-89 grains; and case volumes of 24 grains and change. You can mix all those different headstamps and get pretty decent results.

The bad news is that the Freedom Muntions’ brass was a clear outlier, with empty case weights of 107-109 grains and case volumes of 21 grains and change. Those differences are significant. Freedom Munitions’ brass is thicker and it doesn’t hold as much powder. And that translates into typical starting charges that are already approaching maximum SAAMI pressure. A handloader could get into trouble very quickly using Freedom Munitions’ brass.

For me, since I’ve already sized and primed that lot of X-TREME brass, I’ll load and shoot it (using what would be a minimum charge for any other headstamp). I’ll not load it again. And I won’t be buying any more Freedom Munitions ammo.

The third update is that I bought another 300 Blackout rifle!

Handloading for a semi-auto weapon isn’t hard. But it is a little more persnickety than a bolt gun or single shot. When developing a load it’s important to know which piece of brass came from which round fired. So you’re constantly getting up and down from the bench. Which is a pain in the ass.

I decided that although my DDM4 PDW will always be my preferred 300 Blackout weapon, I needed a development platform. I needed a bolt gun.

And so a Ruger American Ranch Rifle (RARR) in 300 Blackout made an appearance. Relatively inexpensive, free-floated 16” barrel, surprisingly good trigger, Picatinny rail for optics, factory-threaded for suppressor or other muzzle device, and using standard, AR-style magazines… the little Ruger has a lot going for it. It’s easily the most-accurate-for-the-least-dollars rifle I’ve ever owned.

It also led me to another truth regarding these ten factory loads.

As I put all those factory loads in front of my chronograph to confirm the difference between my 7” Daniel Defense PDW and the Ruger’s 16” barrel, the numbers showed up pretty much as expected.

Except that the Gorilla load sometimes just went “click.” With a light primer strike.

Invariably, re-inserting the dud round and triggering the rifle again would have the bullet going down range as it should. But “clicks” are not good.

It’s well known, of course, that the floating firing pin in an AR-style weapon generates more force against the primer than does the spring-driven firing pin in a bolt gun. So the fact that I had experienced no misfires in the DDM4 PDW didn’t particularly surprise me. But the question still remained. Was it sloppy chamber dimensions or a weak firing pin spring in the Ruger? Or was it the Gorilla ammo – either dimensionally incorrect or with an unusually hard primer?

A Sheridan slotted case gauge revealed that the Gorilla ammo was consistently within spec. But, interestingly, extracting a dud round that had just gone “click” – the exact same cartridge that had spec’d okay just a moment before – when now dropped into the Sheridan gauge… showed the round a couple thousandth’s short. The force of the firing pin hitting the primer, although not enough to ignite the round, was enough to drive the cartridge case forward those couple of thousandths.

I’m still investigating the Ruger/Gorilla ammo imbroglio – I have a Field headspace gauge inbound. In the meantime, I have put a question mark next to the Gorilla ammo.

So where does that leave us?

Well, in the supersonic arena the Barnes 110 gr. Vor-Tx load remains hard to beat. I plan on duplicating the factory offering as soon as the several hundred Barnes bullets I have on backorder make their appearance. Having a cheaper handload that has the exact same ballistics and terminal performance as the factory load will be very helpful. I’ll still buy as many of the factory rounds as my budget will allow.

The Remington 130 gr., HTP load (using a Barnes TSX bullet) is also an excellent round. I’m developing a 125 gr., handload (using a Sierra Matchking bullet) as its practice doppelganger. I’ll be buying more of the Remington stuff when I can find it.

For subsonics, the updated Corbon 220 gr., load will be my go-to. I’m just about as happy with the Winchester 200 gr., offering, though. I’ll be buying more of both of those. And I remain very eager to get my hands on the Discreet Ballistics 188 gr., Selous Machined Expander rounds once they come off backorder. I expect there may be a new king of the subsonic hill once they show up… but we will see.

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Re: 300 Blackout - A Tale of Ten Loads

Post by pj-schmidt » Thu Nov 12, 2020 11:07 am

Interesting report and update.

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Re: 300 Blackout - A Tale of Ten Loads

Post by 20X11 » Thu Nov 12, 2020 12:30 pm

As a long time (Old Dude) shooter and reloader, the 300 BLK changed a few things for me;
A) SD doesn't really mean much in an AR platform 300BLK... it's more about accuracy at a given distance. The old bolt gun/singleshot rules around SD don't apply to near the degree they used to when I was loading and shooting benchrest/hunting rounds.
B) The accuracy of your chronograph matters. Most of the cheaper chronos are accurate to 10-15%.
C) Brass DOES matter as you found out with the X-TREME headstamp
D) a couple of inches difference in barrel length makes a HUGE difference in velocity, especially with the shorter barrels (not so much over 16 inches)

So, although I found your write up the have some great info, it was generally missing the group size and distance you shot at. Also, I'm curious what chrono you shot over/with.

I too get great statistical numbers with Barnes 110gr, but NONE of my 300BLK platforms/barrels can make that round group...(Daniel Defense, CMMG, PSA, AAC)...not even in handloads using the Barnes projectile. Granted, I gave up after about 400 of them.

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Re: 300 Blackout - A Tale of Ten Loads

Post by Regaj » Thu Nov 12, 2020 1:18 pm

20X11 wrote:
Thu Nov 12, 2020 12:30 pm
... I'm curious what chrono you shot over/with.

I too get great statistical numbers with Barnes 110gr, but NONE of my 300BLK platforms/barrels can make that round group...(Daniel Defense, CMMG, PSA, AAC)...not even in handloads using the Barnes projectile. Granted, I gave up after about 400 of them.
I use a LabRadar.


Like you, I'm a long-time, old-school shooter. I settled on 100 yards many decades ago as my benchmark for testing centerfire rifle rounds. The 300BLK is the first caliber I've ever really changed up with that... most of my testing to date has been at 50 yards. Given the limited use case that a PDW usually represents - and the lack of a magnified optic - that seemed to make the most sense to me. But the 300BLK certainly has utility beyond typical civilian self-defense distances, and I'll be shooting at greater distances over time.

I'm looking forward to trying my hand with those Barnes bullets, whenever they show up. Hopefully I'll have better luck!

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Re: 300 Blackout - A Tale of Ten Loads

Post by dellet » Fri Nov 13, 2020 12:13 am

Base to datum measurement will likely hold the answer to the Gorilla misfires, post it if you have it.

Any ammo with the 147-150 grain FMJ military bullet will shoot like bulk military ammo.

A chronograph is mandatory for any work with subs as you noted, but you also need minimum expansion velocity on the bullets. Many factory rounds in short barrels won’t expand at muzzle velocity.

Many specialty bullets perform best on the shelf where they can just sit there on look cool. They open too easily, expand too far and stop too soon. This is enhanced when shot through clothing.

Never mind the ones that open in flight.

So yes, there is a lot of testing to keep you occupied with this cartridge if you enjoy collecting data.

Nice write up, thanks for sharing and look forward to more.
300 Blackout, not just for sub-sonics.

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Re: 300 Blackout - A Tale of Ten Loads

Post by BobinNC » Fri Nov 13, 2020 1:26 am


Good report, intelligent and well written.

Thank you for sharing it with us.

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