Quietest SUPERSONIC AR-15 caliber to suppress?

Greyhunter

Greyhunter

New member
I mainly only have experience with suppressing a 16" mid-length .223 AR-15 so far and it's still a bit loud, but I have very sensitive hearing from previous abuse. I do have an adj gas block which did help reduce port popt. I am planning on building a 20" .223 AR upper to suppress as my research says it should have approx 24% less muzzle pressure than a 16" (= less muzzle blast) and the rifle length gas should have a little less port pop, and of course it will be 4" farther from my ears.
I know there are a lot of guys here shooting .223 as well as wildcat cartridges. Before I buy a .223 barrel, I'm curious if anyone has found a cartridge that suppresses noticeably better than .223 (in a comparable barrel length). It would be nice to stick with .223 but I do reload if there was a significantly quieter cartridge out there.
I have a SilencerCo Omega and Hybrid with .223 endcaps for both.
Thanks

EDIT: Opps, meant to post this in the suppressor section so I moved it over there.
 
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Less powder, less noise. Depending on your average shot distance, I'd look at a 300BO pr a 221fb if you can get it to feed reliably..
 
Have you given any thought to one of the pistol AR's. 9mm, 40, 45. Don't know what ranges you shoot at, but they should be almost silent at 1080 fps and below.
 
I understand that a fair amount of the noise comes from the supersonic crack but that isn't what bothers my ears. Suppressed 22 mag and 44 mag both have a loud sonic crack but they don't bother my ears (bolt guns) so it's muzzle blast and port noise that is bothering me with .223.
This upper is for thermal night hunting so I'm going to stay with supersonic ammo because range estimation is tough and shot distances will vary from 50 to 200+ yards.
I've heard some say that supersonic .300blk is quieter than .223 but I don't have one to test out, nor know if it is a significant enough difference to mess with. I have heard the same about 6.5 Grendel. I'm wondering if it is due to the larger bores?
 

This my AR pistol soon to be an SBR in June.
That will be 8 months, I hope.
300 Blackout 10.5in with a Specwar 7,62.
Midwest full forearm. SB Tactical brace.
Only action noise, With SIG sub 208gr loads.


OROojNu.jpg
 
Originally Posted By: willy1947
This my AR pistol soon to be an SBR in June.
That will be 8 months, I hope.
300 Blackout 10.5in with a Specwar 7,62.
Midwest full forearm. SB Tactical brace.
Only action noise, With SIG sub 208gr loads.


OROojNu.jpg


How is it with 300blk supers, compared to a .223? Can you notice any significant difference? I'm fairly sure subs won't do what I want for my use.

I have an SBR stamp pending also for an 11.5 upper. I want an SBR because America and all that, but the more I think about it and read about it the Gemtech Integra sounds better. It is more than a sbr with an integral suppressor and all the reviews say it is the quietest SBR upper out there. It's very expensive but when you look at the components and the total package it really isn't that high priced. I can get one locally for $1600 + stamp. That's kind of a different project than this upper though.
 
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the supersonic noise of a 300 blk suppressed vs a 223 is similar - but it also depends on the powder used.


the 300 blk, because of its case volume rely's on what are typicall magnum pistol powders. because of how they burn they're not always the quietest powders to suppress. you'd have to fool around a bit to balance both sound and function.


bear in mind that the cycling action of an ar-15 is somewhere close to the 100 dB range itself.

i'd say both my 223 (20") and my 300 blk (16" carbine gas rifle and 9" pistol) are both about like shooting a 22lr unsuppressed - give or take. I can shoot them without hearing protection, but prefer not to as i've already done enough damage to my ears over the years from doing silly things before suppressors were legal here in michigan. however - with the suppressor on - even basic foamies are more than sufficient to make for a pleasant day of shooting.
 
Originally Posted By: GreyhunterOriginally Posted By: willy1947
This my AR pistol soon to be an SBR in June.
That will be 8 months, I hope.
300 Blackout 10.5in with a Specwar 7,62.
Midwest full forearm. SB Tactical brace.
Only action noise, With SIG sub 208gr loads.


OROojNu.jpg


How is it with 300blk supers, compared to a .223? Can you notice any significant difference? I'm fairly sure subs won't do what I want for my use.

I have an SBR stamp pending also for an 11.5 upper. I want an SBR because America and all that, but the more I think about it and read about it the Gemtech Integra sounds better. It is more than a sbr with an integral suppressor and all the reviews say it is the quietest SBR upper out there. It's very expensive but when you look at the components and the total package it really isn't that high priced. I can get one locally for $1600 + stamp. That's kind of a different project than this upper though.


I shoot mostly sub Sonic's 209gr and 220gr They make no noise at all.
I own one suppressor, a Specwar 7,62. I learned on this site a few years ago to buy this one.
$200/suppressor $200/SBR. What is in the picture is an AR Pistol.
When, I get my SBR tax stamp. I will change the lower and stock.

With 150gr Fiocchi round it sounds like a 22LR.
My SBR stamp is due the end of June.
 
300BLK or 6.5Grendel.
The length of the barrel makes a big difference.
Longer barrels are much quieter.
We hunt with the 6.5 the most.
 
Originally Posted By: farmerbob300BLK or 6.5Grendel.
The length of the barrel makes a big difference.
Longer barrels are much quieter.
We hunt with the 6.5 the most.

Interesting. What barrel length were you using with 300BLK, and did you compare any other lengths? I built a 20" .223 upper with the hope that it would be noticeably quieter than 16" and other than getting less port pop with the rifle length gas system, I didn't notice it being any quieter. My SBR stamp came in and I'm thinking about building a 300blk upper for subs and supers, trying to decide on a barrel length for it.
Also, would you say that the 300 is quieter than the 6.5 with supersonic ammo?
Thanks
 

I am going to try this one more time. The question is "Quietest SUPERSONIC AR-15 caliber to suppress".

I have a AR15 Pistol with a 10.5in barrel. My Can is a Specwar 7,62. When, I shoot 208gr(SIG)or 220gr (Remington) Ammo all the noise is from the action. My CZ 527 300 Blackout 16 in barrel with the Specwar 7,62 the only noise is the firing pin falling.

I hope this helps.
 
Yes, supersonic is the goal for my thermal coyote setup. Having had the opportunity to shoot a 9" 300blk with subs I can see that it is drastically quieter, and it's not just the lack of the sonic crack. I believe 300blk is just a lower pressure lower powder round. Now that I have my SBR stamp I'm looking for an upper for it and 300 makes sense for some of what I do like coon calling and other shorter range hunting.
As for supersonic, I suspect that 300blk will be a touch quieter, but possibly not enough difference to mess with. Especially given that it's trajectory isn't quite as good as 223.
Shooting the 20" 223 suppressed does not seem very loud for 3-5 shots, but a couple hours later I start to get a dull headache. It doesn't bother a lot of people but my ears are just in bad shape unfortunately. Still MUCH better than unsuppressed.
 
Originally Posted By: Greyhunter I believe 300blk is just a lower pressure lower powder round.

the 223 remington and the 300 blk both have the same saami max pressure spec 55,000 PSI.

yes the 300 blk use less powder - because of the decreased case capacity due to being a cut down 223/5.56 case, as well as how much bullet may or may not extend into the body of the cartridge - but pressure is not solely about how much powder is in the case. its also directly related to case fill %, type of powder used (burn rate), and several other factors. some of these factors will correlate to the dB of suppressed fire, others will not.




http://saami.org/specifications_and_information/publications/download/Z299-4_ANSI-SAAMI_CFR.pdf

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