Subsonic 556/223

[Pain103]

I’m interested in getting a box or two of subsonic 556 or 223 rounds. Would prefer it would cycle properly. I have no first hand experience so I’m seeking opinions good or bad. 

[Alleycat72]

1st of all, they exist. 

Do you load your own? 

What are the specs on the gun?

Are you willing to load duplex loads?

It's much easier with a suppressed sbr, but double with a 16".

You'll need to experiment a bit, but they are 112 gr expanders. 1 in 7 or faster twist.

[Snaveba]

Hickok45 discussing subsonic .223

 

[tmauto769]

22 hours ago, Alleycat72 said:

1st of all, they exist. 

Do you load your own? 

What are the specs on the gun?

Are you willing to load duplex loads?

It's much easier with a suppressed sbr, but double with a 16".

You'll need to experiment a bit, but they are 112 gr expanders. 1 in 7 or faster twist.

I was wondering what class of powders would you use for this? Same as 300blk subs or something else?

[Alleycat72]

1 hour ago, tmauto769 said:

I was wondering what class of powders would you use for this? Same as 300blk subs or something else?

The first thing is heavy round nose flat base holow points in the 112 gr range. I actually have some on the way for a guy now.

You're not going to use 300 blackout powders. What you use is very dependent on the gun setup if you want a unmodified barrel and we really don't want to open up the gas port. We want to keep the gun normal for supersonic rounds. You need to tune the peak pressure to the gas port position. A suppressor is a must. One with back pressure helps.