Reloading subsonic .223

[ace4059]

I am looking to reload some subsonic .223 for my SBR with use of a Ranger 2 can. I have read that subsonic .223 is not much better than 22 LR but I would like a round that is quite. I do not care if it does not cycle the action.

I found several people asking for reload information on the internet, but no real data. The best info I have seen so far is this old thread http://m4carbine.net/showthread.php?t=21709&highlight=subsonic+.223

Does anyone have any new info for load data that will be fairly silent?

One last question. Can too little of a powder load be harmful for your gun or silencer? Blow up the gun or cause baffle strikes because too slow of speed to stabilize the bullet. The reason I ask is because I read on the internet that too little powder in the case can cause a pressure spike in the gun and blow it up or the bullet may not stabilize. I know not to believe everything I read, but I just want to make sure.

I've only reloaded for bolt actions, never for my AR and certainly not subsonic. Any Advice?

[sandsunsurf]

I'm not an expert, but I'm familiar with some of what you're looking for.

Stabilizing projectiles can be an issue. Make sure you know your twist, and test rounds without your can to make sure they are not keyholing.

Use proper powders. From what I have learned, too little rifle powder can cause pressure spikes as you mentioned. My research led me to Trail Boss for subsonic .308. I bet that's what you will end up with. Too little powder can also lead to a squib load. Use more powder and work down. If you aren't certain you saw the bullet hit down range, then check your bore.

With an AR-15 you are going to have weird cycling issues. My friend ended up with a pretty custom bolt and bcg to make his AR cycle with subs (think blowback action like simunitions).

Search snipers hide for sub sonic loads or google .223 trail boss.

[markm]

We've done it successfully with .308, but not .223 yet.

We'll probably try trailboss for .223 too... Try the round with your can off to make sure it's stable before silencing it.

[mtrmn]

We've done it successfully with .308, but not .223 yet.

We'll probably try trailboss for .223 too... Try the round with your can off to make sure it's stable before silencing it.


I have worked up my first 223 sub load using 55gr FMJ bullets. The load I settled on was 4.4gr Trail Boss. 4.6 gr broke the sound barrier and I had the telltale crack on about 50% of the rounds. All my rounds were quiet with 4.4 gr. This with CCI #41 primers and mixed brass. I have not done any accuracy testing yet.

Need to test the rounds on cardboard at as close a range as possible (like 6") to insure the bullets are stable when exiting the barrel. I set up 3 sheets of cardboard at different ranges and shoot all three at once to test stability. At the muzzle, about 10 or 15 feet and the 3rd at about 20 yds or so. Only after several have passed that test do I attach the suppressor. Any keyholing at all and that load does not get any more consideration.

Since I don't have an adjustable gas block, the action will attempt to cycle just barely. The bolt carrier appears to move about 1/2" and then closes back. This gives my AR a sound similar to a Daisy BB gun. The bullet hitting a target at 50 yds is the loudest sound.

[Fried Chicken Blowout]

So you mean these subsonic loads do not cycle the action? It becomes a single shot gun?

[chadbag]

So you mean these subsonic loads do not cycle the action? It becomes a single shot gun?

I think yes, that is what he is saying.

I wonder if you could get a different BCG of some sort -- lighter weight and maybe a different spring and buffer.

You can get 9mm ARs to cycle. Maybe some of the same? Just thinking out loud.

[mtrmn]

I'm not saying it's impossible to get an AR15 to cycle with subs, but it would take some extensive mods/experimentation that would render it useless with full power ammo IMO.

For my uses, the subsonic ammo in an AR15 is not much more than a novelty item. It's a lot of fun getting the gun as quiet as possible and could be useful in pest elimination, but that's about it. I'm no "Operator"--just a guy enjoying his hobby playing with guns.

You're taking a screaming-fast round and reducing the powder charge to below the speed of your average off-the-shelf bulk 22LR. Even with 75 grain bullets, just how reliable will the results be in a serious situation? Also, bullets intended to fly at 2500 fps and above may be hard to stabilize at 1050fps etc, causing baffle strikes. By reducing the power, you pretty much eliminate the ability of your gun to cycle. This is to be the accepted norm I would think. I fully expected to hand cycle mine when I went into the experiment.

Any serious undertaking on my part would be with full power ammo which is plenty quiet suppressed IMO.

[wahoo95]

You can find subsonic 223 load data on Hodgdon website. They have two loads....ones uses Trailboss and the other uses Titegroup. I have used he Titegroup load and not experienced any issues.

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[ace4059]

I got some TrailBoss powder and I loaded 50 rounds. I will have to go to the range next weekend. Ill post up my results. Im going to see if the rounds are stable and if so, then I will try them with the suppressor.

I loaded most with 4.0gr of trailboss and I loaded a few with 3.6 gr. On another forum, a few said the 4.0 grs breaks the sound barrier, and a few had good luck with 3.6 gr. COL is 2.200 with Sierra 55gr GameKing bullets.

Here is a youtube video of a person shooting subsonic .223 loads.
http://www.youtube.com/watch?v=xiUqB-LCHhA

[mtrmn]

I got some TrailBoss powder and I loaded 50 rounds. I will have to go to the range next weekend. Ill post up my results. Im going to see if the rounds are stable and if so, then I will try them with the suppressor.

I loaded most with 4.0gr of trailboss and I loaded a few with 3.6 gr. On another forum, a few said the 4.0 grs breaks the sound barrier, and a few had good luck with 3.6 gr. COL is 2.200 with Sierra 55gr GameKing bullets.

Here is a youtube video of a person shooting subsonic .223 loads.
http://www.youtube.com/watch?v=xiUqB-LCHhA


I know you'll be doing the stability tests first so it will be easy to verify that each round made it out the barrel, but if you have ANY rounds that don't sound/feel/look like the others, make sure the bullet did not stop in the barrel.
It's usually recommended to start out high and work your way down to subsonic levels rather than work up like normal reload processes. Apparently some have had squib loads that lodged bullets in the barrel. I have had no trouble personally, but I just started this stuff as well. Just a heads up if you didn't know.

[ace4059]

I got to shoot my rounds I reloaded yesterday.
I shot the 4.0 gr of trail boss, and the 3.6 gr of trail boss.

I liked the 4.0 better. It held zero (I shot it at 10yds, 25 yds, and 50 yds). I didn't try it past 50 yds because I figuered I would not ever need it past 50 yds for varmints.

I shot about 5 rds of 3.6 but it just seemed "too slow".

I "tested" the 4.0 loads in a phone book, wet newspaper in milk carton test, and 1/8" mild steel plate test. The 3.6, 4.5, and 5.2 where just tested in a phone book.

Remember, these are just subsonic rounds, with sierra 55 gr. game king rounds. I shot these from a 14.5" SBR with a Ranger 2 suppressor. They are extremely quite. the only thing I can hear is the hammer.
The 3.6 gr load did not expand and I could literally see the round flying through the air. The zero was off (4" low) and it had too much wind drift (5" drift) at 50 yds.
The 4.0 had the same zero and was better on wind drift. Only 1" drift at 50yds with 25 mph winds. The bullet did not expand in the phone book nor in the wet news paper. It did not penetrate the 1/8" MS plate.

Next I tried 4.5 grains of trail boss on the phone book test. It penetrated maybe 1/2" more than the 4.0 and it tried to expand. The plastic tip broke off and the nose opened very little. But it still did not expand. This round was still subsonic and only a little louder than the 4.0 load, but still nearly silent.

Then, I did a load with 5.2 grains of trail boss. This load broke the sound barrier and it had a nice crack of the bullet. Not what I am looking for, but in the phone book, it had about the same penetration as the 4.5 grains, and this bullet expanded somewhat.

So the bullet goes trans sonic somewhere between 4.5 grs and 5.2 grains. I didnt do any more loads to see exactly at how many grains it breaks the sound barrier.