300 Blackout SBR (short barrel rifle)

It is Christmas Eve, the sun is out & the temp is 70 degrees. I’m home alone, as my wife stays with her 100 year old mom several days a week. So what to do? How about head down to my home range & do some shootn’! Today I’m shooting my favorite rifle… my 300 Blackout.

300 5

So to begin with, it is a SBR… short barrel rifle. The barrel is 11.5 inches long, as opposed to a standard 16″ carbine barrel. To have such a barrel, I had to apply to the government, the ATF, to get checked out & approved. The approval form is called a stamp & it costs $200 to apply for one. I like to shoot SBRs because I also shoot with a suppressor. The added length & weight of a suppressor to a carbine length barrel is just excessive for me. The gun just isn’t balanced. But put a suppressor on a SBR & it just feels & looks natural to me. Oh, by the way, you have to get a stamp for each suppressor too.

300 Blackout ammo is relatively new.  What I like about it is that it shoots a much larger & heavier bullet than a standard 5.56 AR.  This gives it really good knock down power.  This ammo also burns all its powder completely when shot thru a short barrel.  And best of all, when using subsonic ammo with a suppressor, the gun is rather quiet.  Not silent by any stretch… but quiet enough you don’t need hearing protection.  The down side is that this ammo is not well suited for long range shooting.  At my age, I won’t shoot anything past 100 yards, so that is a non factor for me.  I mostly shoot subsonic ammo as it is much quieter than high velocity ammo.  With high velocity ammo, you get a very loud crack as the bullet passes thru the sound barrier.  By using ammo that stays below the speed of sound, you don’t get that loud crack… plus the ammo itself is a bit quieter.

300 ammo

This rifle, as with any AR styled rifle, is exceptionally easy to shoot.  There is almost no kick, it is very quiet with the suppressor attached, and it is simple to aim.  I use an Aimpoint Pro red dot sight with backup iron sights that fold down when not in use.  The Aimpoint will run for around 3 years on a single battery, but if the optic were to fail in a crisis, the backup sights pop up & you can see them thru the nonfunctional Aimpoint.  This is called a co witness.  In the pics below, note the backup sights down and then up.

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300 1

For this rifle, I use a Saker 7.62 suppressor with quick detatch.

300 4

Since 300 Blackout ammo & 5.56 ammo is so similar, I use solid black magazines for my 5.56 and use the translucent (see thru) magazines for 300 Blackout.  And with the 300 Blackout, I use 20 round magazines for the subsonic ammo & use 30 round magazines for high velocity ammo.

The upper is an AAC SBR 300 Blackout upper.  I use a Stag lower.  And below, is pictured my home range located in my bottom pasture.

range 3 small


  • Comments (34)

    • 3

      That’s a beautiful SBR build Redneck!

      Did you see that the ATF is opening up eForms for suppressors/SBRs and the like?

      • 2

        Thanks!  I sure hope approvals come in as quick as 90 days.  That is a big improvement over the 9+ months for my stamps.

      • 1

        For sure!

    • 2

      Good article and images, the AR platform is an ideal basis for a preppers GP carbine,  I think we may see police and some military move from 5.56 to 300 blackout in the coming years.

      • 4

        I too think the AR platform is close to ideal for preppers.  Folks not familiar with the platform don’t realize it has a buffer & spring in the stock designed to absorb the recoil from shooting.  This is one of the reasons this platform is so comfortable to shoot.  IMO, the concern over a gun’s kick is what keeps most folks from shooting accurately.   Once my trainees realize the gun isn’t gonna hurt their shoulder, they shoot much more accurately.


      • 1

        I think that PERHAPS if our budgets would stand it the H & K 416 with the better gas system would be a worthwhile investment, but only if it was likely you were going to fire a lot of ammo 🙂

      • 1

        Hey Bill,

        Highly doubt any military will move to 300 BLK over 5.56, maybe some specialized swat units, and I’ve heard of tier 1 guys using them in certain scenarios, but not regular mil. It’s too much of a niche cartridge still and it’s main benefit is for suppressor use.  5.56 is a much more versatile and widely available cartridge. The main appeal of 300BLK is the ability to switch between super and subsonic ammo, most 7.62×39 loads actually outperform the supersonic 300BLK loads. However 300BLK is much easier to use for an AR, as it uses the same bolt and mags(for the most part) as a 5.56

        As for the HK416, while it is a sick rifle it is incredibly over priced for what it is and HK doesn’t even sell the version with the good barrels to civilians because they hate us. If you’re dead set on a gas piston system then look at offerings from POF or LMT. Although with modern ARs you really get diminishing returns once you get over roughly the $1,300 mark. The average user will never push a rifle like a BCM to its breaking point, so anything beyond that is just paying for minor increases in efficiency.

      • 1

        I too doubt any military would completely switch to 300 Blackout, however I could certainly see the police doing so.  Police rarely need a hot round like the 5.56 or the 6.8 that I believe the US military will eventually switch to.  Case in point is that shooting in the store in Los Angeles where the police shot an AR inside a store loaded with customers.  One bullet hit & killed a young girl hiding in a dressing room.  I question why they thought a high velocity rifle was the proper weapon in such a location?  In that case, it might not have made any difference what gun was used however in general, using a high velocity round in a crowded, public place ain’t smart.  I cringed as I watched their body cam footage showing them hunting the assailant with ARs.

        Since 300 Blackout ammo is based upon the 5.56 round, my understanding is the only part that actually has to be changed when going from 5.56 to 300 Blackout is the barrel.  I say technically because I understand the 300 Blackout has different gas requirements to properly cycle the action… especially with certain barrel lengths & ammo combinations.    In my case, I simply purchased a 300 Blackout complete upper & put it on my 5.56 lower.  That way, I knew the gas system stays properly tuned for each round.  I’ve never had any failures with either caliber.  Takes all of 30 seconds to switch calibers when using complete uppers.

        If someone, like me shoots both 300 Blackout & 5.56, then there is possible danger in putting the wrong magazine in the wrong gun.  They share the same magazine & it could be rather ugly if you did insert the wrong magazine by mistake.  That is why I use translucent mags for 300 Blackout & solid black for 5.56.  At a glance, I know exactly what caliber is in which magazine.

      • 1

        What’s interesting about that Redneck is that 300BLK rounds are actually more like to punch right through interior walls than certain 5.56 loadings, as the round is heavier and tends to stay together through barriers. Very high velocity, lightweight 5.56 rounds, especially polymer tipped ones, are actually less likely to overpenetrate as they begin to expand and dispel energy after contact with a barrier, even drywall. Here is a good article about it with pictures of the testing. As you can see the pistol rounds zipped right through (and subsonic 300BLK is very similar to a hot .45 load) while the polymer tipped lightweight 5.56 rounds began to tumble and fragment very quickly. The rounds in the picture below are what I keep in my home defense rifle, as my house is 4 sided brick so I’m confident they won’t escape a brick wall.


      • 1

        When shooting inside, I look for a bullet that will penetrate 12″ of ballistic gel but will not then penetrate a sheetrock wall.  Last thing I want is a bullet to pass thru an intruder and possibly hit someone on the other side of a wall.  Several folks have reviewed ammo so it is easy to find reviews of ammo that meets this criteria.  For my 300 Blackout, I happen to have a large stock of Barnes 110-grain VOR-TX TAC-TX, which has outstanding reviews.  Just so happens, this ammo is also a great hunting round.  It is exceptionally accurate!

        It is high velocity, not subsonic, yet with that ballistic tip, the bullet expends all its energy upon impact… and will not then pass thru an interior wall.  If I were to use a rifle for interior home defense, I keep a 30 round magazine of this ammo next to this gun.  I would probably use a 9mm handgun but I would have no reservations in using this rifle with this ammo.

        300 barnes

        Here is a pic of one of my boxes.  

        300 barnes box


        Ammo Review: Barnes 300 AAC Blackout 110gr TAC-TX

      • 1

        That would be exactly the round I would recommend to folks for home defense in 300BLK, it’s well known for its performance. I was referring to a straight impact on drywall with no prior penetration, but you are correct that round is the best for home defense purposes as far as 300BLK goes. Polymer tipped rifle rounds have really redefined what kind of performance you can get out of a cartridge. 

    • 1

      I haven’t shot too many rifles since being in a wheelchair but what I remember is that the very long ones were harder for me to shoot and hold because I don’t have the same core strength that I used to have. 

      Applying for a shorter AR with less weight further away from the body sounds appealing to me. I didn’t know that was an option but do now, so thanks for telling me about it.

      Beautiful gun by the way.

      • 2

        I would highly recommend the S&W 15-22.  It is not a true AR, but is patterned off of one, so the vast majority of AR parts & accessories work on it.  It is made mostly of polymer, so it is considerably lighter than an AR… and is much cheaper too.   Functionality is the same as an AR and it is used as a trainer by many police forces.  My 15-22 has the same stock, sights, trigger, grips, etc. as my 300 Blackout.  I trade optics & accessories between the two.  It shoots the 22LR so there is no kick at all.  I shoot the 15-22 more than all my other guns combined and it is the first gun I use to teach new shooters.

        When I first got my stamp to shorten its barrel, I went ultra short… I think 4 1/2″ long.  Since I mainly shoot subsonic ammo with my suppressor, I found I was having some failures.  I think that length barrel was just too short for subsonic ammo, however if worked perfect with standard high velocity ammo.  So I swapped barrels with another user on the 15-22 forum and then had that barrel cut down to 11 inches.  That works perfectly with subsonic ammo and since my Sparrow suppressor is 5 inches long, my overall barrel length is back to standard carbine length… 16″.

        Here is a pic of a friend shooting it and acting like a redneck.  He used to help me around the farm & is from Nigeria.  He had never shot before but became an avid shooter.

        IMG_0127 small

        IMG_0126 small

        Here is a pic of the 15-22 below my 300 Blackout.


      • 3

        That’s the coolest .22 I’ve ever seen! I’ve never seen a 15-22 fully modded out

      • 2

        Oh, I’ve seen them with lots more attachments.  I add & take away attachments all the time.  I sometimes add a 3x magnifier, on a flip to side mount in front of the sight… as seen on the 300 Blackout.  I have a tactical light that I sometimes use on either gun, especially if going out at night.  I added a barrel nut modification, which allows the 15-22 to accept any AR handguard.  My 15-22 wears an aluminum Samson.

        All attachments pop on & off in an instant, so I only keep those on the rifle that I need at that moment.  I like to keep my rifles as clean & lightweight as possible.  Here are some pics with the light attached.  Note this was back when I had the ultra short barrel.

        high-front small

        side small

      • 2

        That might be the way to go for me. I could probably handle the larger round and the recoil, but with how pricey ammo is I don’t think I’d shoot it as much as I want. But .22lr is a much cheaper and fun round to shoot.

        Thanks for the suggestion Redneck. 

      • 1

        You are welcome.  I think the lighter weight 15-22 would help you out.  The 22LR is cheap and great fun to shoot in the 15-22.  It used to be real cheap, a couple of years ago.  I bought several cases of 5000 when CCI Standard Velocity was .05 a round.  I bought my 300 Blackout at .75 a round, so it is easy to see the benefit of using 22LR.

      • 1

        Plug for the FN P90  civilian version  🙂 However I am a rabid 22LR fan, esp the S&W 15-22 and the Ruger 10/22 , Insanely cheap to shoot, you can get budget ammo and high velocity ammo. And I think 22LR is an under rated round for putting critters in the pot and protecting the homestead.

      • 2

        Bill, I agree completely regarding the 22LR.  It can most certainly put plenty of critters in the pot and most certainly be used to protect your home.  It really shines when paired with a suppressor… especially on a bolt rifle.  With that setup, a suppressor almost does become a silencer.  Mine sounds like a bb gun being shot.

        Interesting thing about 22LR is that subsonic ammo is more accurate than high velocity.  The 22LR design is not well suited for passing thru the sound barrier.  That is why target shooters use subsonic ammo.  Plus subsonic still carries plenty of foot-pounds of energy at the muzzle to take down small game.  And as I stated earlier, there is no loud crack since the bullet stays below the speed of sound.

        My bolt action CZ, with suppressor & scope, makes a great hunting rifle.  True story.  A few years back I had a true redneck on the farm doing some work for me.  This is a guy that lives to hunt and loves to take squirrels with 22LR.  He saw my range so I asked if he wanted to try shooting suppressed, as he never had before.  When he saw how accurate the CZ was and that it was practically silent… he flipped out.  He said there was no limit to how much small game he could take with that setup. 


      • 1

        CZ 22 Bolt guns are very popular over here as well, they are unbiquitous guns found everywhere.   22LR is probably the most common  calibre this side of the pond (I think)  and bolt action guns very popular as Semi autos are banned. 

    • 3

      Nice build, even better range. Did you do your own backstop? We’re buying land in a couple months and I need to add one.

      How hard is 300Blk subsonic to find? It’s be a good round for my location, still have to be selective but better than one going a few thousand yards. Just got a PCC in 9mm as well, it’ll work for now.

      10/22 is a favorite gun of mine, tempted to get the suppressed barrel, I have the TD version. With the 25 round mags I’m less tempted by a 15-22.

      • 3

        Sorry for the delay.  I didn’t notice this post.  Yes, we built the dirt berm backstop, and it is rather large.  We used the dirt that they dug out for the pond.  In this pic, you can see the berm being built behind where they are digging the pond.


        From what I can tell, all ammo is hard to find and none is at a good price.  I always stock up when supply is good & price is low.  Seems price now is about double what I paid a few years back.  This is a lesson for all shooters/preppers.  Try not to buy when demand is high.  I have enough ammo to last me the rest of my life, so I can still enjoy shooting when others find it hard to do so.

        Yes, the Ruger 10/22 is a fine rifle and I have shot one a bit.  For me, I wanted an AR trainer and a 22 LR rifle where I could swap attachments with an AR,  That is where the stock 15-22 shines.

      • 1

        Good deal thanks. Our land could probably use a small pond as well, might be a good way to go about it. 

        Question about suppressors, I know you have to buy them and file the application that takes forever… does the paperwork follow the suppressor? Or is it weapon / suppressor combo. Wondering if a 22 suppressor could could on my 10/22 and a 22LR bolt gun, or a small can on a 9mm handgun and already threaded PCC? 22 is tempting, I don’t really feel the need for hearing protection on the 10/22, suppressed it’d be a breeze. 

        Good share, Happy New Years to all. 

      • 2

        The stamp is for the suppressor, so you can use that suppressor on any gun you wish.  For what it is worth, I like shooting 22LR suppressed better than any caliber.  With 22LR, it actually comes close to being a silencer… especially on a bolt gun.  On the 15-22, the loudest sound is the action cycling after the shot.  After that, 300 Blackout is the next quietest. 

        I think a pond can be one the most important resources for a prepper.  Besides the water itself, they can hold a tremendous amount of fresh meat, that will keep reproducing.

      • 2

        Appreciate it. Might have to consider a threaded barrel for the 10/22 TD… I find it plenty accurate at 15-25 yards to eat forever. Recent article about rabbit (and assume squirrel) poisoning would be a bigger concern if I needed to eat. I was thinking chickens for easy food, but great point about a stocked pond…

      • 3

        Chickens are another great source of protein on a farm but they do require a lot more work and a lot of effort to protect them from predators.  I used to have chickens but gave up because the predators kept killing them off… even with me trying everything possible to protect them.  Unless you have bald eagles, like I do, nothing much will attack your fish in a pond.

    • 2

      If anyone wants to make an SBR but doesn’t want to pay the $200 tax stamp or ask the government what they can do with their firearms they can always slap one of these on their “rifle” with a barrel less than 16″ and it will now be classified as a “pistol” and therefore not require an NFA stamp. What you then decide to put on your weapon whilst in the woods is your business.

      • 2

        Yes, that is one method of bypassing the ATF and using a short barrel… today.  Problem is, this is allowed because of a ruling by the ATF and the way I see it, they could change their mind any time.  I personally prefer making a SBR the way the law intended and not skate by on a ruling that could change.  Making a SBR with a stamp is protected by law.  Making a SBR with a brace is protected only by a ruling.  But I understand why some folks use a brace.

      • 1

        The way I see it they’re all protected by the 2nd. But that’s a conversation for a different place

      • 1

        Sounds like the brace route is gonna get a lot more diecy come August.

    • 4

      Thought I’d let folks know how I reload magazines, after my range time.  Yes, you can load magazines without any tools but it can be a tad rough on your fingers.  I use a Lula loader, which just snaps on the magazine just like your magazine snaps into your rifle.  This tool requires no hand or finger strength, is super fast & super easy. You simply just pull the lever on top forward… then back.  With each motion, room opens up in the magazine for you to simply slide the round in.

      Here is the Lula snapped in place.  Note, no room for the next round.

      lula 10

      Lever pulled forward, which pushes the ammo down & created room for the next round.

      lula 11

      Next round inserted and no room for next round.

      lula 12

      Lever pushed back, and now there is room to slide in another round.

      lula 13

      I just love these loaders.  You can get them for all sorts of rifles & pistols.  They surely make reloading a breeze.

      lula 5

      Here is a video review, so that you can see it in operation.


      • 1

        I’ve heard of the lula loader but good to hear that it actually works.

      • 1

        Oh yes, it works great!

      • 1

        I knew it.

      • 2

        I need me one of those.