How to reduct muzzle blast w handloads

[hboothe]

Hey, all. I'm not even sure how to phrase the question to search for this so if it's been covered, please provide a link.

I have: 12" .223 Wylde SBR w YHM Turbo, AR-15. A friend of mine has: 11.5" .223 Rem SBR w YHM Turbo, AR-15. My SBR is significantly louder to shoot than his when I use "light loads" that I handloaded thinking they'd be quieter. That problem brings me here to ask about loads.

About a week before my tax stamp came in for the Turbo, I was at my friend's working on tuning one of my AR's. He had his 11.5" SBR mentioned above and we shot it. He had factory-loaded Federal (IIRC) 55gr and some 69gr (IIRC) from maybe Federal, maybe someone else (it didn't matter to me at the time). It was appreciably quiet, even with lots of trees around to bounce the sound back at us. I got my stamp and, knowing short barrels yield loud reports, I loaded some cartridges with Hornady 40gr V-Max bullets and H335 at 24.2gr, 0.1gr below the Hornady-listed "minimum" amount, CCI #41 and to the Hornady-manual COAL. I tuned my gas block to get the rifle to cycle reliably with the light loads. No problem. But, wow, LOUD. I sighted it in at another friends place and he was fishing with his daughters about 400 feet away, on the other side of the pond (it's a darned big pond) dam and he commented to me later about how loud the rifle was, knowing it was "suppressed".

Yesterday I was at my ranch and caught a couple of stray dogs there. That, and the random coyote, is the reason for having a suppressed SBR in the truck (canines and my for-profit goats and sheep do not mix well). I'd left a mag full of 69gr SMK handloads and 63gr SSA cartridges alternating in the SBR from when I'd scouted another property for hogs a few days before. I noticed the rifle was quieter. Hmmm...

So, all that background to ask these questions, please: Why would a "light" load cause so much of a report? What should I do (or which component should I look at) to reduce the report of the rifle? I'm using a light bullet to try to get back some of the velocity I give up by going light on the powder (low end of the range). Clearly, a short barreled rifle is likely going to be louder than a 16" or longer barrel...but the same rifle (and another similarly set up SBR) is/are quieter with different cartridges. Since I have no way to quantify the sound pressure level of the rifle, I do not want to just start "trying powders" to see if one is quieter as I'd have no objective way to compare the results. I'd like to understand the cause of the "problem" better before I just start throwing guesses at it, and that's why I'm here asking for advice.

Thank you.

--HC

 

[boltfluter]

Just a thought, but you might try a faster powder to burn as much powder in barrel, and not suppressor.

Paul

 

[hboothe]

Just a thought, but you might try a faster powder to burn as much powder in barrel, and not suppressor.

Paul

Thank you for the reply. I will hit the BR chart later and see what I have on hand. If I have what I need to try it, I will and I'll let you know. Thanks again.

--HC

 

[Zero333]

Hotter load will burn more of the powder and the powder will burn faster with the hotter load.

 

[Uncle Ed]

I shoot 25.0 grains of H335 with a 55 grain bullets in my 16 inch AR15 carbine and I wonder what would happen if you would go up in bullet weight with a faster powder. Normally with a silenced .300 Blackout they are shooting heavy bullets at lower velocities. And you are shooting a very light bullet with a slower burning powder in a very short barrel.

Also Quickload gives you the percent of powder burned for a given length barrel and you might want to rethink your bullet weight and powder.


Shooting the Lightweight AR15 Pistol Project – Loads for AR Pistols & SBRs Part 2
https://www.ammoland.com/2017/08/shooting-lightweight-loads-ar-pistols-sbr/#axzz5m2huFN9D

Hornady BLACK™ 5.56 Nato 75gr InterLock® HD SBR™ is designed specifically for 10.5"-11.5" SBR’s by using proprietary propellant technology and a bullet designed with technology from industry leading Critical Duty® FlexLock® bullets. This round provides exceptional ammunition performance in SBR’s suppressed or unsuppressed, with virtually no flash or residue, dramatically reduced sound signature, will not foul or overheat suppressors, uniform velocity and accuracy, and provides controllable rate of fire in automatic platforms. Designed to meet the requirements of the FBI protocol, this round is the optimum choice for 10.5"-11.5" barreled 5.56 rifles.

 

[lb-ft]

Many have had very good luck with H335. I quickly developed a strong dislike for it for reasons of the report alone. Impressive fireballs and report disproportionate to the cartridge.

 

[Zero333]

Just a side note....

Ran some #'s in Quickload with 12" barrel and 69smk @ 58,000 psi...

Alliant AR-Comp burned 99.8 % of the powder and produced one of the top velocities.

Viht N-120 burned 100 % of the powder in the 12" bbl, but was also 120 fps slower than AR-Comp.

Other powders that burned 100 % were way to fast, such as Win-296, Lil'Gun/H110.

 

[craig55]

Call YHM. They do a lot of R&D when designing and testing suppressors. They will have good info.

 

[DaveTooley]

H335 is the cause of your problem. I shot it in a 223 wildcat in BR. Spectacular muzzle flash on the first shot out of a clean barrel. I still have probably 10 lbs. of surplus 335. Go with one of the modern designer powders.

 

[MikeMcCasland]

A couple of thoughts here...

Barrel length, powder, and suppressor type are only parts of the equation. A lot of what makes all ARs loud (especially the shorter carbine gas systems like you're running) is early bolt unlock/cartridge dwell time (i.e. port noise).

You may want to look at heavier buffers, springs, and an adjustable gas block to slow down that unlock; I'm betting if you have an adjustable block on there now, if you turned the gas off it would be noticeably quieter.


Lastly, shoot heavier projectiles. It's been my experience that faster moving projectiles 'crack' quiet a bit louder.

 

[Rsadams]

H335 is the cause of your problem. I shot it in a 223 wildcat in BR. Spectacular muzzle flash on the first shot out of a clean barrel. I still have probably 10 lbs. of surplus 335. Go with one of the modern designer powders.

Always has a movie style flash..lol , I know guys that load it for just that reason , it throws a nice fireball at night....

 

[dellet]

Many of the things mentioned here will be helpful and predictable. Faster powders normally produce less muzzle pressure, burn more completely and have less flash. Those are all considerations. Some powders are just plain loud. Anyone who shoots Hodgdon loudshot in a pistol will attest to that.

Generally speaking, reducing a load using a loud powder will only make it worse. You lower the burn rate, have more unburned powder, and more muzzle pressure. If anything you want to increase the charge or seating depth.

Since you’re not shooting subs, you want the most efficient/complete burn at the lowest muzzle pressure. This gives the suppressor less gas and sound to mitigate.

At the back end at the ejection port you want to delay the unlocking of the bolt as long as possible, and limit the excess gas. If the system wasn’t over gassed the begin with, it will be with the suppressor atratched. An adjustable block turned down to minimum needed for the bolt to lock will make a noticeable difference.

LMT makes an enhanced carrier that has a lengthened cam path that delays unlocking, it makes a noticeable difference in sound at the shooters ear. It also makes shooting an AR a bit less hard on the brass, it had more time to cool and shrink in the chamber before extraction.

Plenty of things you can do after finding a better powder, but a loud powder can’t be helped much.

I don’t shoot 223 so can’t give a recommendation, but the principles will hold true for any cartridge.

 

[2506]

Most ball powders like H335 cause your problem. Give, depending on bullet weight, IMR 8208, Varget, RL15 stick powders a try.

 

[atblis]

Ill echo what most are saying here. I typically shoot WC844 and XBR8208. Out of my 12.5" with a muzzle brake, I've found the 8208 to have no flash, less concussion, but is much more gassy. WC844 has a huge muzzle flash.

 

[hboothe]

Thank you for the reply. I will hit the BR chart later and see what I have on hand. If I have what I need to try it, I will and I'll let you know. Thanks again.

--HC

Thanks for all the replies. I realized really fast when the first few replies came in that I'd approached this task improperly. Furthermore, I had no faster powder than the H335 which was also in "book recipes" for the .223R. I'm out of town this weekend but picked up some other powders to try when I get back. I did want to post this to say, "thanks for the replies, I'm not abandoning my post/question, but I cannot do hands-on testing until I return early next week, I'll carefully read and address the other replies at that time".

--HC

 

[hboothe]

I shoot 25.0 grains of H335 with a 55 grain bullets in my 16 inch AR15 carbine and I wonder what would happen if you would go up in bullet weight with a faster powder. Normally with a silenced .300 Blackout they are shooting heavy bullets at lower velocities. And you are shooting a very light bullet with a slower burning powder in a very short barrel.

Also Quickload gives you the percent of powder burned for a given length barrel and you might want to rethink your bullet weight and powder.


Shooting the Lightweight AR15 Pistol Project – Loads for AR Pistols & SBRs Part 2
https://www.ammoland.com/2017/08/shooting-lightweight-loads-ar-pistols-sbr/#axzz5m2huFN9D

Hornady BLACK™ 5.56 Nato 75gr InterLock® HD SBR™ is designed specifically for 10.5"-11.5" SBR’s by using proprietary propellant technology and a bullet designed with technology from industry leading Critical Duty® FlexLock® bullets. This round provides exceptional ammunition performance in SBR’s suppressed or unsuppressed, with virtually no flash or residue, dramatically reduced sound signature, will not foul or overheat suppressors, uniform velocity and accuracy, and provides controllable rate of fire in automatic platforms. Designed to meet the requirements of the FBI protocol, this round is the optimum choice for 10.5"-11.5" barreled 5.56 rifles.

Thanks for the reply. I followed the link. While that write-up was not exactly on par with my goals, it was informative. I'm working towards a solution and information gleaned there will be included.

I'll post my current status after I finish replying to the various posts.

Thanks again.

--HC

 

[hboothe]

Many have had very good luck with H335. I quickly developed a strong dislike for it for reasons of the report alone. Impressive fireballs and report disproportionate to the cartridge.

Thanks for the reply. I can attest to the #%^& report. Yessir... I've not shot the load at dusk/night, but it would be most interesting to have a video camera rolling and try some in low/no light conditions. But the bang is awful and not in-tune with having a suppressor. I don't expect .300BLK subsonic/suppressed quiet...but, it can be better than the H335 gave me behind those light bullets.

--HC

 

[hboothe]

Just a side note....

Ran some #'s in Quickload with 12" barrel and 69smk @ 58,000 psi...

Alliant AR-Comp burned 99.8 % of the powder and produced one of the top velocities.

Viht N-120 burned 100 % of the powder in the 12" bbl, but was also 120 fps slower than AR-Comp.

Other powders that burned 100 % were way to fast, such as Win-296, Lil'Gun/H110.

Thanks for the replies. I don't have QL. After looking at it I decided it was probably not in my future for my uses. This attempt to develop a load is way off the reservation for me; I normally stick to book loads and only dabble "within the lines". Thanks for running the numbers. I have some SMK 69gr, but I have neither AR-Comp nor Viht N-120. I've bought a couple of other powders to try (a few days ago, on my way out of town). If those fail to give the results I'm looking for (or if, upon reading my current progress/thoughts later on, you run those numbers and they're garbage), I may try one or both of those powders you listed.

Thank you again.

--HC

 

[hboothe]

Call YHM. They do a lot of R&D when designing and testing suppressors. They will have good info.

Thanks for the reply. I'd not thought of that. I will attempt to contact them to see if they have and will share any such information.

--HC

 

[hboothe]

A couple of thoughts here...

Barrel length, powder, and suppressor type are only parts of the equation. A lot of what makes all ARs loud (especially the shorter carbine gas systems like you're running) is early bolt unlock/cartridge dwell time (i.e. port noise).

You may want to look at heavier buffers, springs, and an adjustable gas block to slow down that unlock; I'm betting if you have an adjustable block on there now, if you turned the gas off it would be noticeably quieter.


Lastly, shoot heavier projectiles. It's been my experience that faster moving projectiles 'crack' quiet a bit louder.

Thanks for the reply. I do have an adjustable gas block and I adjusted it to cycle and lock back on empty with the first rounds of 24.2gr H335 and the 40gr Hdy V-Max, so it wasn't massively overgassed. The SBR has a standard buffer and spring in it. I have an H2 JP Silent Captured Spring I could use and a Tubbs flatwire... However, after hearing how much quieter the heavier loads were, I going to try a few more load solutions before I start changing components of the rifle. But your points are valid and have been noted.

--HC