Making subsonic .223

[rm9792]

I want some subsonic for playing with my suppressor. However, what ammo i find online is rare and expensive. Can I remove powder from my existing rounds to make them subsonic?
If so, is there a load table available somewhere so I know how much powder to put back in?

[rm9792]

I reload 45 and various 50's but have never done any with tapered necks. If someone here can do me 100 rds or so i would be glad to pay them.

[MoJo]

Subsonic ammunition for rifles is tricky to produce since there is very little data available. Downloading factory loaded ammo can be dangerous there is a phenomenon known as detonation where very small charges of powder in rifle cases will explode with devastating results. What I would do is look for some loads that are low power low pressure and use them. Hodgdon lists these loads for .223 that may do the job. They will not cycle the action of an AR and are recommended for bolt action rifles.

COL Grains Vel Pressure
55 GR. HDY FMJ IMR Trail Boss .224" 2.200" 4.0 1074
55 GR. HDY FMJ Hodgdon Titegroup .224" 2.200" 3.1 1064 4,000 CUP
55 GR. HDY FMJ Hodgdon Clays .224" 2.200" 3.2 1060 3,700 CUP

[rm9792]

Thanks, I had not heard of that. This is why I asked first! I guess i will keep looking for factory loads.

[Houston1944]

If you are worried about detonation then find a copy of Speer manual #14 and read page 48, it is also covered in issue #13.

The real danger of such reduced loads is the bullet not exiting the barrel and the shooter firing another round. Speer lists several 223 "reduced loads" in their manual but they are simply reduced recoil loads, not subsonic. it would take some very special powder slection to move a bullet the lenght of a rifle barrel and not exceed the speed of sound. I have an extra 223 barrel that I do not mind beating stuck bullets out, maybe this winter when I am bored I will try to push some slow moving 40 gr bullets thru it.

[threoh8]

What kind of rifle? If it's an AR15 - based rifle, I'd sure consider a .22LR conversion for quiet shooting. Subsonic .22LR ammunition is readily available, and would be very, very quiet in a suppressed rifle.

[MoJo]

To be subsonic a bullet should have a velocity of < 1114 FPS to produce a velocity that low safely in a .223 is going to be daunting to say the least. The range will be severely limited and accuracy might suffer from insufficient stabilization. The suggestion of a .22 LR conversion is a good one but most of them won't work reliably with standard velocity ammo much less subsonic.

[gigag04]

Might check on Weapon Evolution or M4Carbine.net as they have a larger NFA following there.

[OldCannon]

Reducing loads can cause a dangerous underpressure, resulting in very nasty explosions. Not to mention that successful shots will likely result in an unstabilized barrel exit (and thus a VERY short life for your expensive suppressor).

The suggestion to go to .22, or scale up to a more suppression-capable caliber (say, 300 AAC) would be a wiser change.

[Jumping Frog]

If you want to tweak a load to be subsonic, use heavy-for-caliber bullets as part of the answer.

[NcongruNt]

IF I were going to do this, I'd go with the Trail Boss powder. It was made for this exact purpose - safe low velocity "cowboy" loads. It's very bulky, so you avoid the potential of detonation that you would have with such reduced loads with ordinary powders.

While it's designed to work best with cast bullets, I've read of folks making low velocity jacketed rifle rounds. Usually they're reduced loads for bolt-action hunting rifles. There was an issue of Handloader Magazine (April 2010) with an article about doing this very thing.

http://www.riflemagazine.com/magazine/i ... ?magid=599" onclick="window.open(this.href);return false;

[CDH]

I want some subsonic for playing with my suppressor. However, what ammo i find online is rare and expensive.

For good reason...it is very difficult, requires the heaviest bullets available and small amounts of fast powder, a tricky combination for safety and near impossible to get to cycle an autoloader not specially set up for the purpose.

Can I remove powder from my existing rounds to make them subsonic?
If so, is there a load table available somewhere so I know how much powder to put back in?

Absolutely not if you value safety. If you choose to dabble in this, get a reloading setup and start with cast loads...they are less likely to stick in a barrel and easier to get out when you do. The Lyman manual is a good start.

There is a reason the 300 whisper and similar rounds were made. The 223/5.56 is not well suited at all for this task.

A 22lr conversion and the Aguila 60 grain SSS load is a better and easier way to accomplish the same thing with a lot less risk.

[Houston1944]

Hodgdon now has subsonic loads for the 223 listed in their on line reloading center with 3 different powders, Trail Boss, Titegroup and Clays and only with a 55 gr bullet. Not sure how long this data has been available, I was checking their web site for 223 loads a couple of months ago and I think I would have notice this.

[MoJo]

I tried some Trail Boss with 55 gr bullets in .223. The loads were definitely sub-sonic but there was not enough pressure to operate the action. I basically had a rather awkward straight pull bolt action rifle. They were pretty accurate at 25 yards. A full power load is more accurate and will cycle the rifle.