Home Forums Hunting & Shooting AR and Tactical Rifles Home Defense 300BLK SBR Questions

I'm thinking about building an SBR, using 300BLK subsonics, that would be used solely as a home defense weapon. I come to that decision based on a balance of factors, including size, weight, performance in a short barrel, penetration, stopping power, and efficiency in suppression.

With that said, I've shot a standard M4 type rifle plenty of times, but I have zero experience with the 300BLK, SBRs or suppressed weapons. So, I have some questions about the process of building such a system. Again, this weapon would literally go two places- the rifle range, for training and maintenance, and my bedroom for home defense.

If I want to keep the thing short and maneuverable, I see their are offerings for 9-11" barrels and 5-7" suppressor combinations to help keep the overall length in the standard M4 length range.

I assume that the subsonics are the best way to go to get the DBs to the point where I don't care about hearing protection. And the ballistic limitations of the subsonics are not an issue at the distances we're talking about for home defense.

How do I take into account the combination of ammo load, barrel length, gas block system and BCG to ensure proper cycling of rounds? For those who have built such a weapon system, did you use an adjustable gas block to tune all those factors?

My concern is to ensure proper and reliable cycling, mitigate excess back pressure that may be created with a suppressor, felt recoil/muzzle jump and management of the amount of gas when shells are expelled.

Also, for such a close quarters weapon, would you even bother with optics or would you just go with metal sights and/or a laser and just point and shoot?

Thanks in advance,
Rob

Maybe look at going the AR pistol route with the 300. That way you avoid the SBR hassles and expense.

First -skip the subsonics. You're not smoking sentries before the assault team moves in. Super sonics will be fine without ear pro in the 300BO in your house and have MUCH better terminal ballistics. Subs aren't even as good as good bullets in a 9mm/40/45acp.


Second- forget the "point shooting" nonsense. Everything is aimed, even at feet. A good red dot with a white light should all but be mandatory for a home "defense" gun.


Third- the best thing you can do is to buy a quality well built upper from one of the better manufactures already set to shoot subs and supers. WAY less hassle.


Fourth- 110gr Barnes Tipped TSX Black tip.

why not a pistol caliber carbine like the beretta storm in 45ACP?

To be polite.....

Because pistol cartridges suck at killing things. Putting them in a rifle doesn't improve things, and in fact hurts as the bullets arent desinged for the extra velocity.

223 and 300BO with supers is a FAR better choice for use against living things.





To be blunt.....

Pistol caliber carbines are freaking stupid. Nothing like getting all the downsides of a carbine with none of the upsides.

But the op asked about 300 BO subsonic. If you launch a 30 caliber 230 gr bullet or a 45 caliber 230 gr bullet ~1000 fps, you have the same ballistics. The only difference is the 30 cal bullet is going to need to really open up, or it will be zipping on through your walls off into the neighborhood.

While our military has mostly moved away from smg's, the Tommy Gun and Grease Gun seemed to have worked pretty well in WWII.

The LeHigh Defense 194gr bullets intended for the 300BO have earned good reports. I tried Sierra Matchkings and an Outlaw State on a doe, and a pig respectively, and was unimpressed.

I keep a Daniel in 300 as the house gun. It is loaded with supers, 125gr Noslers, which I have seen work well on pigs. It's basically a .30 carbine on steroids, which is fine with me.

I looked hard at pistol Caliber carbines, and all of them seem to wind up with funky features that turned me off, or were of uncertain quality. The .45 ACP AR lowers that accept grease gun mags are pretty interesting. I have to think a 230gr Gold Dot at 1200 fps will be very effective. But it's not a cheap option.

I was just thinking a 45ACP 230 grain gold dot from a small carbine would be easier to hit with equipped with a red dot and flashlight. Even the 124 grain HST's in 9mm in a carbine. Not sure but would not the 300 BO with a 110 grain barnes penetrate more "stuff" than a 124 grain HST from a 9mm carbine?

Not even close. Pistols cartridges (9mm/357/40/45/etc) are literally the worst at penetration of indoor structures while also having the smallest wound channel.

Once again- pistol caliber carbines SUCK for real use. There is nothing you can dream up to take the stench away from that.


And again, increasing velocity on pistol bullets DOES NOT increase performance. It DECREAES performance. Modern pistol bullets are designed to perform exactly at their correct velocity window. Adding FPS hurts them.









Because they didn't have anything better. There is not one that would pick a SMG over a M4 based 5.56 or 300BO. And as soon as they had the early 5.56 carbines they dumped the SMG's immediately.


A super sonic 300BO or 5.56 with a can will be fine without ear pro if needed for its purpose and has the rather not insignificant benefit of better tissue damage, less risk of over penetration, better platform, etc, etc, etc.

I don't always agree with with Formidosilus, but am 100% in agreement with him on this stuff.

When you hear someone talk about wanting to use 300 Blk subsonics for reduced penetration in a home, you can be sure that person does not have any experience with this stuff. There is a very limited selection of bullets that actually perform correctly in subsonic 30 cal rifle loads of any headstamp, and if you use anything else, penetration through meat and home building materials is astronomically higher than a good 223 or 300 supersonic load.

I don't know why people have such a hard time wrapping their head around supersonic 300 loads. It's just a 7.62x39 in an AR15, with better bullets and without the feed issues. No more, no less. It's not a 30 carbine, or a 30/30, just a better development on a common soviet cartridge that's proven to work acceptably well all over the world.

110gr Barnes from a .300 BO - indeed impressive



but a 230gr Gold Dot at 1167 fps is not shabby. This is from a .460 Rowland, which is probably close to what a .45 ACP would do from a 16" barrel

I get the love for ARs (I've got some) but for strictly "home defense" indoor ranges, I'll stick with a 18-20" barreled shotguns. For protecting a larger property where outdoor ranges come into play, then an AR makes more sense. Just my opinion.

Pistol cartridge carbines generally provide pistol cartridge ballistics, but shooter has an easier time shooting accurately............which is a big deal, and justification for the platform IMO.

This is a good time to actually listen to the "Been there, done that" guy....

I've looked hard at tactical shotguns, too, but can't warm up to them, either. Even a quality unit, like a Benelli M4, will be longer and clumsier than an AR, and hold fewer shots. The M4 is pretty spendy, too.

If the bullpups like the Kel-tec KSG were known to be reliable, they might be an option, but so far I'm not willing to shell out the cash to be the guinea pig.

Compared to an AR in 5.56 or 300 Blk? No. My 6 year old can shoot a 5.56 AR.

Benelli makes great autos, but aren't the only reliable autoloader out there. Certainly one of the most expensive though.

Regarding ammo capacity, there's probably a security blanket feeling that comes from a 30rnd mag, but a shotgun with a 6-10rnd capacity (and more ridding outside) is no slouch for HD scenarios. If you accept that most threats engaged with a carbine will receive multiple rounds (on the trigger until the threat drops) all of a sudden your 30rnd mag, even if divided by a conservative three shots, gives the user ammo for 10 targets. But at HD ranges, the trauma from a single round of buckshot will likely suffice. Different wound characteristics, but lots of damage nonetheless.

There's always a doomsday scenario where a whole biker gang comes into your home at the same time, but realistically (at least for me) 8rnds in the gun with more riding on it is enough to not feel under-gunned. YMMV, and that's OK.

If you want your six year old making shoot/no-shoot decisions, that's your call. I was referring to adult shooters, and either pistol caliber carbines OR 5.56/300BLK carbines are easier to shoot quickly and accurately under stress than handguns.

Way to throw false arguments into a reasonable discussion. Grow up and try to follow the conversation. Nobody else was discussing handguns or shoot/no shoot decisions.

YOU brought up a 6yr old.

I agree the AR adapts to pretty much every size and shape of shooter, but why mention a young child?

My point in the previous post was that pistol cartridge carbines DO have the advantage of shooting said rounds more accurately than from a pistol. Nothing more.

And yes, pistol calibers were discussed earlier in this thread.

I just struggle to understand how a 45 ACP 230 grain gold dot out of a pistol sucks, but sucks more out of a 16 inch carbine. A dollar a shot practice ammo vs 50 cents a shot or less. Beyond the ammo cost I agree 300 is a far better round.