5.56 Subsonic rounds?

[Guest WOOTEN]

I have serched on the boards,and asked a couple of friends, with no reall answers. So I will ask you all here, Whats a good subsonic round or Nato 5.56 / 223?

[dlm37015]

10.5 to 11.0 grains of aa5744 will cycle your action but why its just a 22lr when you do that oh thats with a 77 grain nosler match bullet

[JeffsSig]

Really David? I tried and couldn't get mine to cycle. Ill try some more and change my seating depth. That might work?

[dlm37015]

i works for me and others i have given it to as well

[JeffsSig]

what are you setting the OAL to?

[Dolomite_supafly]

I use 4.5-4.7 gr of Trailboss with 69 SMK's. I load the bullets backwards to identify them. The flat point also hits harder.

They will not cycle but more importantly they do not unlock letting gas escape.

They are stabile in a 9 twist barrel at subsonic velocities.

Dolomite

[broylz]

id be more likely to use a 22lr conversion with the 60gr SSS ammo. work is already done for you.

[Dolomite_supafly]

But with a conversion using 60 grain SSS you get A LOT of port noise. It is because the casing is so short it can't seal properly as well as allowing a lot more gas to escape before the barrel pressure drops. Standard subsonic rounds are quieter than the SSS in a AR conversion when you take into consideration the port noise, which is loud enough to ring my ears. Another problem is the escaping gases tend to fly back into the shooters face when shooting the SSS.

I have also milled weights and added them to my conversion to try to keep the bolt closed longer. And even when the weight began to cause cycling issues it still was giving me a lot of port noise. I know using a conversion in my AR the ejection port noise is louder than hitting steel at 25 yards when using them.

The ejection port noise is louder than the same round out of a bolt gun without a can. With a can in a bolt gun the round is amazing but not in any semi auto.

The key to getting a round as quiet as possible is to catch and slow the gases down. Because the SSS opens so early the gases are still fast and hot when exiting the ejection port.

Dolomite

[Guest WOOTEN]

Thank you everybody for your help, I am planning on picking up TAC 15. If that work I will be forced to come up with a reliable subsonic round answer. Thank you again...

[ted]

Try some of thease http://store.drtammo.com/index.aspx