[Eric2340]

General AR Pistol barrel length question?

When one drops below the normal 16" carbine length into the shorter pistol barrel lengths (let's say below the 10" to the 7.5" PISTOL lengths), it's my understanding that the energy level drops OFF, but the noise level goes way UP?


I understand at distance the energy level is an issue, but at interior HD distances, is this really such an issue as much as the noise level is?


Trying to decide if I just want to stick with a standard 16" AR, or dip my toes in the AR pistol world for a strictly HD AR pistol style gun?

(I am also looking to stay away from getting into the tax stamp / SBR / running a can on a shorter barrel issues also is why I am asking about AR Pistols (w/ a brace on them) specifically)


* NOT looking to get into makes or models, strictly want to discuss AR Pistol (when running a brace on it) barrel lengths at this point to decide if I want to go pistol or just stick to a standard 16" AR.

Thanks -

 

[Mongo444]

Well, it's a pistol. One held like one holds a rifle. Shorter the barrel, that's what happens. There'll be gives-and-takes. "At Distance?" It's a pistol. CQB and all guns are loud.

If the noise is an issue, go to a different gun range. Otherwise, if the SHTF, noise-level will only will bother you the most!

A suppressor would definitely be nice, but then you just went from pistol into the rearview mirror in terms of firearm length.

Now, I don't know ANYTHING about suppressor-effected performance, so I'm just giving you my off-the-cuff thoughts (w/a little guff for fun). Anyway, just my opinion. I want an AR pistol as my "next." It will fulfill a very important role in my self defense sensibilities.

 

[Zerodefect]

Don't drop under 14.5" for 5.56. Larue makes some great kits with a nice comp pinned and welded. 5.56 indoors from a 8" barrel is instant deafness. Not a practical tool at all.

For home defense I've seen very little gain from pistol AR's. 14.5 is plenty small. Otherwise consider a Scorpion or PS90.

Another option is .300 blk. All .300blk barrels are piston gas, and it uses pistol powder, so it's perfect for short barrels. But they're very finicky with mags. 20 round metal mags seem to be best. .300blk solves all of the 5.56 short barrel problems, the trade off is mag issues.

 

[J-Doo]

Here’s how I figure it. If I end up shooting my AR pistol inside my house I’ve bigger issues than the noise. I’m not trying to be a smart a**. I have flash cans on my AR pistols (KAK, KX-5, etc) and they do help at the indoor range as they push the blast away from you. I’m not sure now much they would help in a house though. I have 3- 5.56 pistols with 10.5” barrels and 2-300 BO pistols one 8” and one 8.5”. They all shoot well. I’ve thought about a shorter barreled 5.56 but I’ve heard they are pretty obnoxious to shoot.

 

[faawrenchbndr]

The increased perceived noise level is due to two things. Muzzle closer to shooter and unburned powder. would not go shorter than 11.5” with a 5.56 upper

as far as AR pistols, I prefer them in 9mm.

 

[Eric2340]

Ok, so I think that pretty much answers my questions - it's not so much power drop off in a HD situation as it is the noise level?


Here's why I am asking all this - I am considering getting one of the SA Saint Victor AR Pistols like this -

https://www.springfield-armory.com/...armory.com/saint-series/saint-victor-ar-15-rifles/saint-victor-556-ar-15-pistol

But from what everyone is saying, firing it in a house in a SD situation, forget it? I don't want to have to put on hearing protection in a HD situation to stop me from being able to hear an intruder also?

Thanks -

 

[87'vette]

Why not get a Pistol caliber carbine for HD? Wont be as loud as a rifle cartridge indoors? There are some nice handgun cartridge AR's out there. :flag:

 

[drumgod]

I wouldn't go below 11.5" as it seems to be a sweet spot right before a significant performance drop-off. My 11.5 pistol is my go-to AR. I built a 7.5" "just for fun" but the performance was so dismal I rebuilt it into a 11" x39.

I weighed using my 11.5 for HD but it is still incredibly loud. I've moved to a PCC (well, PCP really) for HD. Super small and light, easy to shoot, and noise levels similar to a standard pistol. As always, YMMV.

 

[syntaxerrorsix]

All barrel lengths are going to be loud.

Here's an interesting link to some testing.

A 10" barrel was reported at 164.3dB and a 16" barrel was reported at 163.3dB

https://ndiastorage.blob.core.usgov...ob.core.usgovcloudapi.net/ndia/2010/armament/WednesdayCumberlandPhilipDater.pdf

 

[hardluk1]

MY wifes AR pistol is a 10.5" 1-7 twist 5.56 upper with a .750 gas port at a 7" and I use a 4.6oz H2 buffer . Its reliable with a variety of 55gr to 72gr 223 ammo and a number of different brands 5.56 ammo 55gr to 62gr .

 

[JMS]

I have a 16", 10.5" and 7.5", I wouldn't say one is excessively louder than another. My 12.5" 308 pistol though....woof!

 

[MarkCO]

I have one .223 set up for Defense. A KelTec RDB with a suppressor on it. Pistols, shotguns and PCCs are before that though.

I agree with the 14.5" as short as I would go on a .223 AR, but mine are 16" with one 17" and one 18". Concussion and operation is more of a concern than terminal performance. I've shot 11.5 and 14.5 in matches and as long as you know the holds, not a big deal.

 

[ScotchWhisky]

300 blackout in a subsonic flavor is probably your best bet for a HD pistol when it come to sound. Question then becomes, is a subsonic round what you really want for HD? Some say yes, but most say go supersonic for any real defense situation.

 

[DADoser]

Ok, so I think that pretty much answers my questions - it's not so much power drop off in a HD situation as it is the noise level?


Here's why I am asking all this - I am considering getting one of the SA Saint Victor AR Pistols like this -

https://www.springfield-armory.com/...armory.com/saint-series/saint-victor-ar-15-rifles/saint-victor-556-ar-15-pistol


View attachment 735840



But from what everyone is saying, firing it in a house in a SD situation, forget it? I don't want to have to put on hearing protection in a HD situation to stop me from being able to hear an intruder also?

Thanks -

Eric -
Funny. I picked up the Saint you are considering about 8 months ago. Loved shooting it - it was a blast - literally. All things considered - i.e. loss of terminal velocity w/ short barrel, loudness in HD situation, etc. ---- I ended up picking up an Angstadt Arms UPD-9 - 6 in barrel. I sold the Saint a week ago. I have decided for me - no AR pistol in 556 with a barrel below 10.5"

 

[SpringerTGO]

I've posted similar stuff in other threads, but here goes.
My 9" 556 SBR would be one of the last firearms I would choose for home defense. Especially without the suppressor. It is insanely loud and the blast would temporarily blind in a low light situation. I'd much rather use 300 BO.
Subsonic 300 BO has much better terminal performance than 45 ACP and the noise and blast aren't any worse. Of course, suppressed it's fantastic. It's also a very versatile cartridge and it's designed for short barrel performance.
If you don't want to go to the expense of 300 BO I'd go with a PCC. I have all 3 options, and for the most part would choose the PCC. It's the least expensive to leave out of the safe, the ammo is cheap and effective, it's small and light. etc.

 

[Eric2340]

Eric -
Funny. I picked up the Saint you are considering about 8 months ago. Loved shooting it - it was a blast - literally. All things considered - i.e. loss of terminal velocity, loudness in HD situation, etc. ---- I ended up picking up an Angstadt Arms UPD-9 - 6 in barrel. I sold the Saint a week ago. I have decided for me - no AR pistol in 556 with a barrel below 10.5"

So did you get rid of it b/c of the noise level when firing it indoors / concern with using it as a HD weapon in your house due to the noise level when firing it?

I'm not really worried about the drop off in level of performance in side the house in a HD level, it's more the sound blast level / hearing damage coming from a .223 in that short of a barrel.

What I really can't understand though is how people are worried about .223 coming out of a barrel shorter than 16" noise wise, and not having the same concerns with lighting off a 12ga shotgun inside a home in an HD situation? Is one not just as loud as the other? Are they BOTH not louder than a defensive size caliber (9mm, .40, .45) going off in a house?

 

[hvyhawler]

I

Ok, so I think that pretty much answers my questions - it's not so much power drop off in a HD situation as it is the noise level?


Here's why I am asking all this - I am considering getting one of the SA Saint Victor AR Pistols like this -

https://www.springfield-armory.com/...armory.com/saint-series/saint-victor-ar-15-rifles/saint-victor-556-ar-15-pistol


View attachment 735840



But from what everyone is saying, firing it in a house in a SD situation, forget it? I don't want to have to put on hearing protection in a HD situation to stop me from being able to hear an intruder also?

Thanks -

Have a set of Walker razor electronic muffs next to my home defense weapons, upstairs and downstairs. Amazon had them for like twenty seven bucks on sale. I have multiple sets. I have a 10.5" 5.56 and a 8.5" 300Blk. Both shoot great out to 100 yards. Will try them at 200 yards weather permitting, we still have and are expected to get snow.

 

[Darkangel1846]

Well having been in a house(kitchen) when someone lit off a 12G! well it was darn loud. I had a AR pistol, it was that KelTec AR pistol. At the range I was shooting 55G. The first time I fired it was loud even with head phones, loud enough that several people came over to see what I was shooting. I really can't imagine shooting inside a house. I keep a pair of electronic head phones at my bed side.

 

[DADoser]

So did you get rid of it b/c of the noise level when firing it indoors / concern with using it as a HD weapon in your house due to the noise level when firing it?

I'm not really worried about the drop off in level of performance in side the house in a HD level, it's more the sound blast level / hearing damage coming from a .223 in that short of a barrel.

What I really can't understand though is how people are worried about .223 coming out of a barrel shorter than 16" noise wise, and not having the same concerns with lighting off a 12ga shotgun inside a home in an HD situation? Is one not just as loud as the other? Are they BOTH not louder than a defensive size caliber (9mm, .40, .45) going off in a house?

View attachment 735950

I don't really do shotguns - home defense or own any. Nothing against, just not my thing.

Noise wasn't the biggest issue. Reading a lot about bullet fragmentation in barrels below 16" in 5.56/.223. Seems like anything below a 10.3" (???) barrel, one is just poking 22 caliber holes in a target at super high velocity.

In a short barrel braced pistol 10" or below - seemed like 9mm (or 300 black out) was the way to go. I just didn't want to add the 300 caliber to my safe/calibers I needed to buy. I went with the UDP-9 for the 6" barrel length and it took Glock magazines (which i had plenty of).

Also I already own a Ruger 556 pistol with the 10.5" barrel. The 7.5" Saint didn't make sense for me to own anymore. However, the next purchase I'm looking at is - Saint Edge Pistol 10.3" in 5.56.

 

[Eric2340]

So basically we are all in agreement here then -

Inside the house / HD -

- Handgun in decent SD / HD caliber (9mm and up)
- Shotgun
or
- 16" .223 or up (AR)



OUTSIDE the house / backyard distance / longer

- 16" or up AR in .223 or larger caliber long gun / shotgun ????



Basically trying to use below 16" AR in the house is just asking for hearing damage or worse?

Thanks -