It's my understanding that I can shoot .300 AAC Blackout on my M&P 15 Sport ii by changing the upper and maybe the BCG to .300.

What are your thoughts for using .300 AAC (and which brand/model of ammo) for home defense, as opposed to .223/5.56?

Thanks!

My Primary HD firearm is a 12 gauge Remington 870 because there is nothing more devastating than a load of #1 Buck and shooting Skeet has made me very adept with a shotgun.

My secondary backup is a home built AR-15 in 300 Blackout. Because at in home distances it just makes a bit more sense in terms of over penetration. I'll also note that the Blackout features iron sights because they are much faster to acquire although I would probably point shoot it like a shotgun.

scooter123, thank you for your reply.

What brand(s) of upper and lower do you have in your home built AR-15 and where did you get them from?

What brand/model ammo do you use?

Thanks

300 Blackout uses the same bolt and bolt carrier group as 5.56, as well as the same magazines, just change out the barrel or have a new barreled upper. I mark all of my 300 Blackout mags, since trying to shoot 300 in a 5.56 barrel leads to "interesting" results that you don't want to experience.

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Only a cold warrior

You could use tan mags for Blackout, for example. Easy to tell apart. I actually have a 7.62x39 upper. Those magazines have a serious curve. Easy to keep the two identified.

I'd use soft points. Standard jacketed will likely way overpenetrate.

I am a fan of the .300 BO in an AR pistol. Ballistics and all set aside, the 5.56/.223 round is super abrasive in a short barrel. I can not imagine firing one inside a house for SD. The .300 BO for the most part is loaded w pistol type powder, and the noise difference between the two rounds is significant.

To keep my mags seperate, I use metal mags for 5.56 and plastic Magpul mags for the .300.

Just my 2 cents,
Tim

good idea. I have mine labeled but a pass with a rattle can may be in their future.

when i shot across the course (and there was an ar mag shortage) i painted my designated match mags painted orange and the one modified with a SLED orange with a white stripe. never lost one while moving from one line to another and never had someone try to 5-finger my mag.

doing a matching patch on my 300bo uppers sounds like a good idea too! as u may guess, i don't really care about appearance over function

Thanks, everyone.

What brand/model of .300 AAC Blackout guns/uppers do you have?

I have rebarreled a Sig PM400 Scorpion Pistol from 556/223 to 300 BLK for the simple reason that it is easier to suppress the sound of a larger subsonic bullet. The gun has a 10.5 inch barrel and I use a Omega 9K suppressor that I will also use on my SigMPX 9mm SBR loaded with 147 grain Hush Puppy rounds from Super Vel. That is my house gun. It’s all about noise control.

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SWCA 3255 SWHF 615

My upper and lower are Anderson's, as Generice as you can get. The Barrel is a 16 inch Wilson Combat, the Trigger a Timney 3 lbs. single stage, the forward handguard is by Gibbz Arms, and sights are Magpul folding. I'll also note that the Gas Block is an adjustable by Syrac Ordinance which do require regular cleaning or they will plug up.

As for ammo, the only ammo I've shot with this rifle are my own hand loads using a Nosler 125 grain bullet. Accuracy is good at 3/4 inch at 100 yards.

My 300 BO is an 8.5" pistol. PSA upper, and a "poverty pony" Anderson lower. It had a Shockwave fin brace on it, which I have since removed. I put a foam cover on the buffer tube, and it is still as manageable as when it had the brace.

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Only a cold warrior

Not in my opinion. Perhaps the difference between a 500 lb bomb and a 2000 pounder. Loud is loud. Even subs are close to .45 auto real world loudness. For short range defense, I wouldn't bother. The danger of getting ammo mixed up is not insignificant. The juice ain't worth the squeeze.

I have 10.5" AR pistols in 5.56 and 300 BLK - with the 10.5" tubes, they both give reasonable ballistics with a variety of rounds I use. With that barrel length, neither is quiet, and neither is heinously loud (the 5.56 was louder but I put a mini-flash-can on it that directs the blast toward the front and now they sound the same to me shooting - just fine). Like my vecino Sistema1927, I mark the 300 BLK gun and mags so as to try to prevent shoving a .3" pole into a .22" hole.

As to your Q, I live in a suburban area and would not consider the 300 for home defense due to penetration issues. Many sites detail how 55-gr 5.56 isn't the worst choice for such usage, but I'll stop short of recommending it.

Both my guns were from PSA pistol kits - one uses a PSA frame and the other an Anderson. Each cost just over $300 after shipping and FFL fees. Both are totally reliable and are readily capable of beating 2 MOA off the bags at 100 yards with factory ammo and just a 2" red dot for a sight. I'm glad I didn't spend more money.

I built the Blackout pistol in order to have a light, small gun with good firepower that can reach out and penetrate at 200 yards for my solo jaunts to the desert - I've worked on too many creepy cases starting out there. I very much like the thing (was just shooting both of the AR pistols last week), but I'm not sure I'd bother with the caliber if I had it to do over - the 5.56 with 75-grain TAP rounds seems like it would pretty much do everything I might ever need. The truth is that I was lured by the siren call of the daily Palmetto State Armory deal emails . . . eventually, they were just too cheap to pass up.

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Now go make God proud...

Also, difference in ammo costs would be significant unless one reloads. But if you never shoot it then it won't matter.

Any cartridge that is super sonic is going to be a yuge problem inside a house. Try it sometime without ear protection and you will probably pass. Hopefully you will regain your hearing over time.

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That's just somebody talkin.

Erich, Thanks.

You wrote: "As to your Q, I live in a suburban area and would not consider the 300 for home defense due to penetration issues. Many sites detail how 55-gr 5.56 isn't the worst choice for such usage, but I'll stop short of recommending it."

Do you mean that the .300 over- or under-penetrates?

And what would you recommend for home defense?

Thanks

Over, of course (not sure anyone in the world would suggest a round of its velocity and sectional density would be underpenetrative for use in a suburban home defense situation).

I don't know where you live (nearby structures) or what your conditions of living (others who may be in the structure) are. I'm sure you can figure out what's best for you in your situation - I'm not able to do that, not knowing all your variables.

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Now go make God proud...

An AR in 5.56, especially short-barreled is a nearly ideal home defense weapon, except for one glaring problem, which makes it nearly unsuitable for the purpose: muzzle blast and noise.

You can easily do permanent hearing damage with a single shot from a short barreled 5.56 indoors.

Otherwise, they work great... precise, high capacity, easy to shoot, excellent terminal performance without over penetrating.

Supersonic, the .300BLK is just as unsuitable as a 5.56 for home defense for all the same reasons, with the additional problem of over penetration. With subsonic rounds, the .300BLK tones that package down to handgun levels. Basically, it's a pointy .45acp in a high capacity, easy handling package that is fantastic suppressed. Unfortunately, it's going to over penetrate compared to a handgun caliber. Not sure if anyone has developed a heavy .30 cal bullet that expands reliably at subsonic velocities.

IMHO, for the average homeowner, a handgun is easier to use for home defense, but if I were to go carbine I would go with a handgun caliber.

That's true. Forgot all about that. Very lucky perhaps 2 yrs ago and got several thousand supers (Outback) when they were having that big sale through Global. Believe it came out to approx 41 cents per round. Sold the 9" pistol and ammo together. Charged only what I paid for the ammo. Could have easily gotten 1.00 + per round. The guy was a very happy camper. Took all the common sense precautions with colored magazines, labels on gun, etc. The gun was great but with a 10 yr old now "ARing", etc, I just wasn't comfortable with it. Sure did like the size of the hole it made though.

Believe all that ammunition was 125s and 144s. One of them was that blackened brass. Had to keep a couple of those rounds for gp.

My lower is Anderson my upper is a Frankenstein I bought used with a Stainless barrel. I already had a suppressor, so I use 220 grain Remington and my handloads (also 220). With this ammo all you hear is the action cycling. I had to cut coils off the buffer spring to get reliable cycling. I use a brass catcher as the brass bouncing all over the place is surprisingly noisy! The muzzel energy is about like a 45ACP, with the higher BC bullet, the effective range is 200 yards (WWII British SAS used silenced DeLille 45 ACP carbines on German sentries at 200 yards, so yes it will work that far!)

Penetration is more than a 45 and less than a 223. (probably on par with 124 gr 9mm.) With this ammo, I wouldn't hesitate to use it for SD. But afterward, explaining it to the cops and DA would be very interesting! Being the one alive to explain it, is the most important part!

Ivan

Ivan

Neither, you don’t need a 200-400 yd battle rifle cartridge to shoot across the room. An excellent way to destroy your hearing or kill a neighbor. Get yourself a decent 4 inch revolver in a +P pistol caliber with a set of crimson trace grips and a good high lume tactical light with a 20-12 ga pump as a backup.