300 AAC Blackout 208 gr Subsonic A-Max and Silverback

Freedom_208gr_A-MaxI’m a HUGE fan of .300 blk and have been shooting it since 2012.

A lot of people don’t understand the allure of the .300 blk, and some think it’s ridiculous. That’s fine, but let me SHOW you why I like .300blk subsonic so much and then I’ll give you some quick background on the bullet and tell you some of the top reasons why I shoot it.

Here’s a quick 3 minute video where I demonstrate the accuracy, high speed controllability, and penetration of the round.

The high-speed recoil part should be of particular interest to those of you who asked for it when I did the article on high speed pistol recoil control.






On recoil control, there are a few things that are making the recoil as manageable as it is.

First, in this case, it helps to think of it as shooting a .45 ACP with a shoulder stock, weight out front, and a vertical foregrip.

Second, and this is most important, I’m using a push-pull grip on the AR that helps control recoil, no matter what the caliber/load.

Many people PULL on the vertical foregrip on an AR, but if you do that and have someone try to grab & move the muzzle, you’ll see how unstable that is.

But, if you PUSH on the vertical foregrip with your left hand while pulling on the pistol grip with your right hand, you cause isometric tension and create a MUCH more stable shooting platform.  This is what allows me to put fast rounds on target up close and followup quickly on medium range targets.

Another benefit of this is that if you incorporate the push-pull into shouldering your carbine, you have enough isometric tension to start shooting sooner and have recoil control BEFORE the butt hits your collarbone/chest.

Background on the .300 blk.

The .300 blk round was designed as a replacement for the suppressed MP5 for building clearing operations that would be hearing safe to use while clearing a building and allow operators to immediately engage short to medium range targets in the outdoors by simply changing from a mag loaded with subsonic ammo to a mag loaded with full power ammo. This does not require any changes or modifications to the gun. This is why it’s so different from the MP5/7 and M4.

Ballistically, the way that I think of subsonic .300 blk vs. full power .300 blk is that the subsonic has ballistics similar to a .45ACP and the full power has ballistics similar to an AK-47 (7.62×39). It’s not a magic bullet…it’s a bullet with a specific set of purposes. The subsonic version is hearing safe and the full power version has solid terminal ballistics out past 300 yards (16.7% more energy than a 7.62×39 at 300 yards).

.300 blk uses, essentially a .223 or 5.56 case that has been resized to hold a bullet that is .30 inches in diameter (think .308, 30-30, 30-06, 7.62×39, .300 win mag, etc.) instead of .22 inches in diameter (think .22, .223, 5.56, etc.)

Instead of pushing a 55 grain to 77 grain bullet, like you would with a 5.56, a .300 blk will push a 110-220 grain bullet.

This becomes an advantage when you want to shoot suppressed, without hearing protection. Since the speed of sound is fixed, the goal is to push as heavy of a projectile out of the barrel as possible (within reason) to thump the target with as much force as possible.

But not all 300 blackout ammo—especially subsonic—is created equally.

For the first couple of years after the 300 blackout came out, subsonic ammunition was ALMOST as hard to find as pink unicorn snot and I bought and shot whatever I could find. When you pay for subsonic ammo, you want it to be subsonic and not have so high of a muzzle velocity that it breaks the sound barrier.

Unfortunately, many manufacturers knew that they could throw crap in a box, slap a 300 blackout subsonic label on it, and get upwards of $1.30-$2 per round for it.

What I found with many brands (including big name brands) was that 2-8 rounds per box of 20 would randomly break the sound barrier. This isn’t just a noise issue…it’s an issue of inconsistency. Many bullets lose stability as they go from supersonic to subsonic speed.  In addition, if you aren’t pushing rounds out of your barrel at close to the same speed every time, you can’t accurately sight in or trust your gun to put rounds where you want them to go.  Moral of the story…know your ammo.  I’ve had very good luck with Freedom Munitions 208gr Subsonic.

I like the .300 blk for a few reasons…namely:

1. When shooting subsonic ammo suppressed (I use a 16” AAC upper and an AAC SDN-6 suppressor), I can stand on my deck with friends & family and shoot without any of us having to wear hearing protection, experiencing ringing in the ears, or negatively reacting to the rounds going off. For longer shooting sessions, I wear hearing protection, even though I probably don’t need to…but I’m in my 40s and my cost/benefit calculations are different than they used to be.

2. Again with subsonic, I can do varmint control around the house in the late evening and early morning without waking anyone in the house or bothering neighbors. Our neighbors aren’t THAT close, but still don’t want to hear rounds going off as they’re going to sleep or waking up.

3. Since the .300 blk subsonic has the ballistics of a .45ACP, I can use it in ranges and shoot houses that don’t allow 5.56 or bigger ammo.

4. Since the .300 blk is made from .223 brass, it fits in 5.56 AR magazines. A 30 round 5.56 magazine will hold 30 rounds of .300 blk and putting .300 blk into a 5.56 magazine won’t cause any surprise malfunctions.

5. Since .300 blk in full power has roughly the same ballistics as 7.62×39, it’ll work for any game animal that you’d use a 7.62×39 or 30-30 on, except it’s more accurate than most 7.62×39 and it’s (arguably) got a longer effective range than a 30-30.

6. It’s accurate.  As I showed in the video, shooting golf balls at 65 yards is relatively straight forward.

Let’s get into the performance of the Freedom Munitions 208 gr. Subsonic A-Max and let me start by dispelling a misconception that you might have.  The fancy red tip doesn’t mean that the bullet is going to necessarily explode or have “devastating” expansion on impact.

Conventional rifle hollowpoints don’t expand well at slow speeds. Most 30 caliber bullets are made to leave the muzzle at speeds up to 3000 feet per second. That means they have to hold together well. The downside of this is that there are VERY few bullets that are designed to expand at subsonic speeds of 1100 feet per second or less.

The A-Max LOOKS like an expanding hollow point with a polymer tip. It does expand when it hits fluids at 2,000 feet per second or more, but at subsonic speeds, the main purposes of the A-Max polymer tip are resistance to nicking & deformation during chambering and pushing the center of mass further back on the bullet to improve ballistic coefficient and flight characteristics.

The penetration of the bullet was actually one of the most surprising things that I found in my testing. It punches through the first 8-10” of water jugs like an arrow…a testament to the aerodynamics of the bullet…before yawing/tumbling and cutting a bigger wound channel.

I found the exact same performance on coyote. It punches a clean, small hole straight through the broadside of coyote. In my limited experience, I found that tiny coyote ribs did little to impact the bullet. The subsonic A-Max hardly a “devastating” round, but it will quietly put lead EXACTLY where you want it to go. If your bullet placement is good, it’s very effective at QUIET varmint/small predator control at close range. I would assume, but don’t know, that the round would be comparable to a .45ACP when it hits the bones of larger predators—creating shrapnel and additional wound channels.  This is not a bad thing on small game…simply view your target 3 dimensionally and put your sights on the organ(s) you want to hit and send it.

Want expanding performance with subsonic rounds?  I ran the first version of this article in 2015 and expanding subsonics existed, but manufacturers hadn’t figured out production yet…they have now.  If you want expansion at low speeds, here’s an update for 2017 that may be your answer:

Gorilla Silverback 300 blackout

It’s the Silverback round from Gorilla Ammunition.  The bullet is CNC manufactured by Maker Bullets and designed to expand at subsonic speeds.

Here’s an example of what a milk jug looks like after the A-Max (left) goes through it vs. after the Silverback (right) goes through it:

With the A-Max, you have to use a scope to see if you hit the jug.  With the Silverback, the jug explodes.

Hunting with subs is a tricky affair.  First, it needs to be legal where you live.  I can hunt with any center fire round where I live.  Second, you need to hunt like an archer.  PERFECT shot placement is vital.  You can’t count on a temporary wound cavity.  Close isn’t good enough.  You have to know your anatomy, your bullet drops at different distances, and execute the fundamentals perfectly…even if hunting causes your stress level to go up.  You MUST test your round and know your DOPE before going in the field.  Animals deserve quick, clean kills.  If you aren’t 100% sure you can do that with a subsonic round, don’t try.

The Silverbacks are $1.50-$2+ per round, but the nice thing about sub-sonics is that bullets of the same weight have the same muzzle velocities and same points of impact within 50-80 yards, so you can practice with cheaper rounds of the same weight and validate with a couple of high dollar rounds before going into the field.

That being said, I can tell you that I’m 100% harvesting deer with subs in the last few years.  One was a heart-double lung shot with an A-Max.  .30 hole in.  .30 hole out.  The deer ran less than 20 yards before dropping.

My last one was a neck/spine shot with the Gorilla.  This time, the deer didn’t even take a step.

As I was showing this video to people, one thing I kept getting asked was what kind of steel target I was using with the resetting flag target. It’s from www.Range-Systems.com. It’s RIFLE rated, and here’s some quick info on it: https://www.range-systems.com/product/ipsc-flag-target-self-resetting-flag/.

A couple of other questions people had…

The first was how to know your bullet drops for subsonic rounds?  Just like archery, you’ve got to put some time in with live fire at the distances you expect to be shooting at, but my long range pistol drop chart that comes with 21 Day Alpha Shooter and Tactical Vision Training will give you rough holds out to 200 yards.

The second thing I heard from people was that they couldn’t see a golf ball at 65 yards, let alone shoot it.  If that’s the case for you, you may want to seriously consider trying out my Tactical Vision Training course.  It helps old (40+) eyes see quicker and clearer and it helps young eyes see quicker and have a wider field of view.  Get it tonight and you may see better tomorrow by clicking >HERE<

With all of the gear shown and examples, this article may very well bring up more questions than it answers.  If that’s the case, let me know by commenting/asking below.  Like the 300 Blackout?  Hate it?  Sound off by commenting below.



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  • Jackie

    Reply Reply November 10, 2017

    I’ve been laughed at, ridiculed, and even given the stink eye for the saddle kit I carry in 45acp.
    Five years ago, I bought the first High Point pistol/carbine set I’d ever seen. After polishing the feed ramps and a few magazine mods, I’ve put 100s of rounds through them doing switch drills at the range. Never a FTL/FTF. With the 14″ barrel, the carbine is an excellent hog gun, especially as the heavy weapon has negligible barrel rise. I shoot routine 3″ shreds at 35 yards with 10 rd mags and a BSA red dot.
    I’m posting because there are a lot of pigs in Oklahoma, and I never failed to kill every one I shot, usually with one round. Almost everyone I hunt with use 30-30, 444 Marlin, 45-70, or 44 mag levers. They all say 45acp is insufficient for hogs, I disagree. Your thoughts, please?
    By the way, push/pull is awesome!!

    • Ox

      Reply Reply November 10, 2017

      With the right shot placement, .45 ACP will do the job on hogs…you just don’t have nearly as much wiggle room as someone shooting a 44 mag. With a faster, heavier bullet, a shooter may decide to shoot through bone. As a defensive pistol caliber hunter (as opposed to a hunting caliber), you have to hunt like an archer and be exacting and particular about your shot placement. The big advantage you have over an archer or someone shooting a heavier, faster load is the speed that you can make followup shots.

      BTW, I love the .300blk, the fact that I can use it on my regular AR lowers, and switch back and forth between subs and full power, but if I was starting over and only planned on shooting subs, I’d get a pistol caliber carbine in .45. I’d be pushing the same weight (sometimes heavier) bullets at the same speed as the blackout at a fraction of the price.

  • Drew Rinella

    Reply Reply November 10, 2017

    I’ve not heard of push pull on a rifle before but it makes perfect sense and I will be trying it out.

    Your subsonic tests in milk jugs would indicate less than 12″ balliatics gel equivalent assuming a ~1.8X water to gel ratio. Fine for coyotes, but I’m curious if you would change to full house loads for SD?

    That expanding bullet looks amazing. I’d need some more convincing from Freedom before dropping the coin on A-Max bullets for short range/sub sonic purposes in any caliber though. Some sort of side-by-side test where the only variable changed is the bullet type, demonstrating the better suitability of an A-Max over Hornadys high performing (and lower cost) OTM offerings for example.

    Great post as always.

    • Ox

      Reply Reply November 10, 2017

      Thanks, Drew 🙂

      What’s “SD”?

      The Gorilla easily goes through 2 milk jugs, “blowing up” both. I can show you terminal ballistics offline.

      On the A-Max, I don’t even see subs on the Freedom site today and the least expensive sub they’ve got is 69c apiece.

    • Ox

      Reply Reply November 10, 2017

      I’m not sure if you were talking about the new Hornady Sub-x…they just filed their patent in July and it’s not in stock anywhere yet, but it’s WAY less than any other expanding .300 blk round and I just backordered 2 boxes 🙂

  • herman

    Reply Reply November 10, 2017

    I use 300 blk out as my “go to” weapons. I have two in SBR (I have the tax stamps), one in my house and one in my vehicle. I always use subsonic 208 AMAX. The home weapon has a suppressor, the vehicle weapon has a linear compensator. I have a red dot on home and a 4X32 on the vehicle platforms; both with BUIS. I have been a fan of the Black Out for as long as you have. In fact, I have sold all but one of my 5.56’s to go exclusively to the 300. Love the article for the info presented and it validates my decision to go with the 300. I would like to hear your thoughts on the buffer/buffer spring on SBR’s. Keep it coming brother.

  • Mike

    Reply Reply May 21, 2016

    What range did you sight in for the 208 gr subsonic in 300 BLK?

    • Ox

      Reply Reply May 25, 2016

      That’s a very personal question…not private, but specific to my situation. Where I live, the longest shot possible in the area where I live, hike, & hunt is 130 yards, and most of the shots are at 60-80 yards, so I have it sighted in at 60 yards.

  • Boyd

    Reply Reply July 25, 2015

    I have been planning a SBR upper in 300BLK for suppressed, subsonic use. I’m amazed how quiet your 16″ barrel is. Are they staying subsonic even with the longer barrel?

    • Ox

      Reply Reply July 25, 2015

      The Freedom ammo is staying subsonic for me, but it’s been incredibly common with other brands that I’ve used to get frequent cracks. Again…it’s not just the irritation of expecting the report to be quieter, but frequent cracks are an indication of inconsistent loading. In other words, with the other brands of ammo, the inconvenience of the crack may not be there, but the loose groups would be.

  • Gary

    Reply Reply July 25, 2015

    I’ve got a300 blackout made by Ambush Firearms. This is the best caliber for hunting hogs in the Texas marsh. We use an airboat so you have to be able to shoot quick at ranges of 30 – 100 yds. I hope to put a can on it soon and try the heavier bullets. Good write up, keep up the good work.

    • Ox

      Reply Reply July 25, 2015

      300 blk is a PERFECT pig gun, although you may want to stick with the lighter, full power loads rather than going heavy/subsonic…even with a suppressor.

      You gain a ton of energy with the extra velocity that really comes in handy on pigs.

  • John

    Reply Reply July 25, 2015

    Love my DD 300 blk. 16 in. Barrel, eotech holographic with fixed four power magnifier.. Currently unsurprised.
    I need more magnification, most 300 specific scopes are low power. What do you think about a Leupold VX-R patrol 3x9x40 with tactical milling reticle? Any recommendations would be helpful.
    Thanks. John

  • N. E. Stickle

    Reply Reply July 24, 2015

    Suggestion, use 221 Fireball brass necked up to 30 Cal.

    • Ox

      Reply Reply July 25, 2015

      For 300 Whisper or 300 Blackout?

  • Laird Taylor

    Reply Reply July 24, 2015

    I’m a recent 300 BLK shooter (subsonic only). I have an AR-15 (re-barrelled with an AAC kit) and a Ruger 6968 – both in 1:7. I’m waiting for the stamp from BATFE (earliest: Labor Day). I have the components and tools to reload 208gr rounds, I found that at 200 yds the drop for factory 220gr is 75″ and time-of-flight is ~5/8 second. The subsonic round is probably excellent for head-on shots of wild hogs (skull penetration). For side shots I’d use supersonic ammo, hoping for fragmentation in softer tissue (the heart).

    Q: the subsonic BLK has legendary penetration (I saw the milk jugs on your video – tnx) and I’m chasing down a rumor (OK – a blogger said so outright, but nobody confirms – yet) that it also penetrates (live) tree trunks up to 13″ diameter and still leaves a wound track in the notional perp hiding behind said tree. While this is not the shot to seek, it may well be tactical reality, if one’s ambient includes oak woods, as here in north TX. Available ballistic data says a 220gr slows from 1020ft/sec at muzzle to 910 ft/sec at 200 yds. Given that, the big deal might well be the terminal ballistics: what does the bullet do to/through live wood?

    I’ll be more forthcoming. The 208gr I’m contemplating using is match-grade Hornady from Cabela’s – arguably not manufactured for BLK use, but for muzzle velocities in the high 2000’s from any of a plethora of high-velocity platforms. My rounds do NOT have the plastic tip, but are copper-jacketed all the way forward – with as high a BC as you could expect to get from an all-metal jacket.

    If you write back “gee – I dunno…” then I’ll make up some ballistic gel and take to the woods myself. The owners of the woods where I’ll do my experiment(s) will reluctantly let me shoot their trees into Swiss cheese – thus my asking here first.

    • Ox

      Reply Reply July 25, 2015

      That’s something that I’d be happy to test out 🙂 I’m still not sure if I’d use subsonic on hogs…the lithmus test I use is that if I’d use a 45 ACP on the animal (both because of the animal and because of the range), then I’d use 300blk subsonic. If it needs more punch, then I use full power.

  • Guy

    Reply Reply July 24, 2015

    1. You said that the 300 blk is made from .223 brass, it fits in 5.56 AR magazines. I assume the full power round does the same… Correct ?
    2. Obviously you are shooting the 300 blk on an AR platform. What would be involved in converting a .223/5.56 AR15 to shoot that 300 ammo ? Just barrel change or is it more involved ?

    • Ox

      Reply Reply July 25, 2015

      Correct on #1. The rounds have to meet the same SAAMI specs, regardless of whether they are full power or subsonic.

      On #2, there are 2 ways to go. I didn’t want to mess around with reliability and didn’t want to figure out how to make it work, so I went with a dedicated 300blk upper from AAC. I simply pop the 2 takedown pins and swap uppers.

      Most people just swap barrels because it’s a much less expensive option.

  • Greg Tolley

    Reply Reply July 24, 2015

    hey there!…I really appreciate all the work & research you do for us out here!
    Would you share w/me all the calibers that are available for use in the AR platform which can also use the 5.56 mags?
    also, when putting together an AR upper for the .50 Beowolf, can all the standard diameter forearms, bbl extentions, upper receiver etc., be used? If not, what specific “parts” are needed?….thnx again for all you do, thnx in advance for your help & God bless!…..Greg T.

    • Ox

      Reply Reply July 25, 2015

      I don’t know all of them that are claimed to work off hand, and it’s somewhat subjective. Technically, 7.62×39 works in an AR mag, but you’re going to see reliability issues.

      50 Beowulf is interesting…besides being a nice big heavy round that works with a standard AR, it’s got a HUGE benefit in that a magazine stamped “50 Beowulf” that LEGALLY holds 10 rounds (in states/countries with magazine capacity restrictions) can hold 30 rounds of .223/5.56. You’d need to check and see if that was legal in your area.

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