Low velocity AR pistol build for HD?

[OldmanFCSA]

my 12 gage loaded with #4 buck is not quiet, including racking the slide after 1st shot

[Holland&Holland]

Anything better to do?

[mc762x54R]

That's gotta be crazy, crazy loud for HD no? You could load a 9mm carbine / SBR and get that same muzzle energy with less powder, noise, etc.
I'm getting 1320fps with a 124gn JHP 9mm in my little CZ Scorpion...480 ft-lbs

It's not unbearably loud. just a little louder than a normal AR according to my wife. My 20 year old daughter was in the house while I was shooting off the deck. She came out to water the plants and was surprised to see that I was shooting. She thought it was weird that so many birds were hitting the windows today.
So it must have not been "that" loud.

I know that a 55gr bullet will have a lot less force at 1900 FPS than a normal 2500 FPS bullet, and a 1320 FPS 124gr bullet may be a lot better. I don't know that. That's what I'm hoping to find out from this thread.
I do have an AR9 build on order, but it could be up to a couple more months.

If you're going to cut the performance down to pistol levels, wouldn't starting with 7.62x39mm make more sense?

Yes - I 2nd this. I have a 16" AR in 762x39, its a ton of fun.

[Bitter Bastard]

That's gotta be crazy, crazy loud for HD no? You could load a 9mm carbine / SBR and get that same muzzle energy with less powder, noise, etc.
I'm getting 1320fps with a 124gn JHP 9mm in my little CZ Scorpion...480 ft-lbs

It's not unbearably loud. just a little louder than a normal AR according to my wife. My 20 year old daughter was in the house while I was shooting off the deck. She came out to water the plants and was surprised to see that I was shooting. She thought it was weird that so many birds were hitting the windows today.
So it must have not been "that" loud.

I know that a 55gr bullet will have a lot less force at 1900 FPS than a normal 2500 FPS bullet, and a 1320 FPS 124gr bullet may be a lot better. I don't know that. That's what I'm hoping to find out from this thread.
I do have an AR9 build on order, but it could be up to a couple more months.

I'd say shoot it back to back with a 16" or 20" AR and then judge the noise. I have a 7.5" SBR that is unbelievably loud and throws a basketball size muzzle flash but the brake can obviously make a huge difference there. Mine has an old DPMS enclosed A2 brake on it. They had an A2 flash hider that has a closed end on it except for a .22 hole for the bullet. Makes quite the racket, which was kinda my point at the time because it is fun. Mine started out as a range toy but I wouldn't hesitate to use it for HD if that is all I had. I'm quite confident it would be effective at in-home ranges, if not exactly the most ideal gun available. There's an old thread on it, accuracy is quite good with an optic, on par with my other ARs, just a lot more drop at 200 yards.

Bitter Bastard

[Scratch]

That's gotta be crazy, crazy loud for HD no? You could load a 9mm carbine / SBR and get that same muzzle energy with less powder, noise, etc.
I'm getting 1320fps with a 124gn JHP 9mm in my little CZ Scorpion...480 ft-lbs

It's not unbearably loud. just a little louder than a normal AR according to my wife. My 20 year old daughter was in the house while I was shooting off the deck. She came out to water the plants and was surprised to see that I was shooting. She thought it was weird that so many birds were hitting the windows today.
So it must have not been "that" loud.

I know that a 55gr bullet will have a lot less force at 1900 FPS than a normal 2500 FPS bullet, and a 1320 FPS 124gr bullet may be a lot better. I don't know that. That's what I'm hoping to find out from this thread.
I do have an AR9 build on order, but it could be up to a couple more months.

If you're going to cut the performance down to pistol levels, wouldn't starting with 7.62x39mm make more sense?

Again, this gun was a spare parts build that I built just because someone gave me a barrel. I've just come to enjoy it a lot, and am considering using it for HD.

[Holland&Holland]

If your HD gun is not a Ma Deuce backing up the Claymores you set than you are doing it wrong.

[Scratch]

That's gotta be crazy, crazy loud for HD no? You could load a 9mm carbine / SBR and get that same muzzle energy with less powder, noise, etc.
I'm getting 1320fps with a 124gn JHP 9mm in my little CZ Scorpion...480 ft-lbs

It's not unbearably loud. just a little louder than a normal AR according to my wife. My 20 year old daughter was in the house while I was shooting off the deck. She came out to water the plants and was surprised to see that I was shooting. She thought it was weird that so many birds were hitting the windows today.
So it must have not been "that" loud.

I know that a 55gr bullet will have a lot less force at 1900 FPS than a normal 2500 FPS bullet, and a 1320 FPS 124gr bullet may be a lot better. I don't know that. That's what I'm hoping to find out from this thread.
I do have an AR9 build on order, but it could be up to a couple more months.

I'd say shoot it back to back with a 16" or 20" AR and then judge the noise. I have a 7.5" SBR that is unbelievably loud and throws a basketball size muzzle flash but the brake can obviously make a huge difference there. Mine has an old DPMS enclosed A2 brake on it. They had an A2 flash hider that has a closed end on it except for a .22 hole for the bullet. Makes quite the racket, which was kinda my point at the time because it is fun. Mine started out as a range toy but I wouldn't hesitate to use it for HD if that is all I had. I'm quite confident it would be effective at in-home ranges, if not exactly the most ideal gun available. There's an old thread on it, accuracy is quite good with an optic, on par with my other ARs, just a lot more drop at 200 yards.

Bitter Bastard

I have shot it alongside 3 other rifles. A 16" with a VG6 Gamma comp, a 16" with a Miculek brake, and an 18" with an A2 flash hider. The A2 was the quietest but I didn't think any of them were obscenely too loud. I've done some expansion testing with the 7" barrel comparing it to a 16" barrel by filling up a 55 gallon drum with water and shooting down into it from my deck. (And getting very wet in the process) I've only tried some soft point and some V-Max so far, but they are both very similar as far as expansion. I'm going to try some other ammo in the barrel soon.

I think I'm also going to get one of those ARmA15 locking mounts for it and hang a jacket over it like in the videos. It looks pretty slick. Anyone have one?

[Rowdy Roddy]

Looks really LOUD. I built an AR-9 for home protection, low velocity and lower noise. Hope you never have to use that in a hurry without earpro indoors or you will pay dearly.

[Scratch]

Looks really LOUD. I built an AR-9 for home protection, low velocity and lower noise. Hope you never have to use that in a hurry without earpro indoors or you will pay dearly.

It is loud, but I didn't think it was any louder than my other rifles. I'm sure it was, but I couldn't tell with ear pro on, and I'm not interested in shooting with them off. I have shot it indoors in a 10x16 room doing some muzzle flash testing in the dark, but again, I didn't notice an obvious difference in noise between it and some of the other rifles.