Aone here Haven to mess with building and dinning suppressed .223 /5.56 ARs ? That long loading subsonics for them ?

I have supressed AR's. Only messed with subs in 300 blackout. Didn't care for them much got away from subs for hunting except For a .22 cal I just shoot cci .22lr segmented subs or hp. I wouldn't gain a thing wasting time to load subs in 5.56.
Sorry I'm not any help .

If you want to shoot sub sonic with a can, go the 22 lr route. There is no point at all trying to slow down a 223 to that level.
If you tried heavy rounds, you would need a heck of a twist rate to keep them stable as they are pretty long for their diameter and at such slow speeds, 1: 7 is not going to give you the RPM needed.
If you go with the lighter rounds.... the 22 LR already does just that and a lot cheaper. And you probably won't get the action to cycle reliably with such light loads without a bunch of other modifications to your rifles bolt / carrier , springs etc.
Just not worth the agro to mess with it. Gets you a 10/22 and screw a can on it and call it good

Well what I'm actually doing isn't shooting suppressed .223 , but the info I need to make it work is basically the same as getting subsonics to work in .223. But anytime I've told people what I'm doing...yeah stone wall

So I don't need to do a thing different to get Any ofmine to run. With suppers. An adjustable gas block would probably be nice and reduce gas to my face other than that I don't know why you need anything different.

You need a = adjustable gas block. That way you can tune rounds as your mission changes. That whau SF does. I can t remeber = Gas block tube size But I think you may have to drill it out some. Go to = Snipers Hide. Find info there. Run something like = 77 gr SMKs and like 10 to 12 grains of = Trail Boss. Unqie Reloader 7. Green Dot or whatever they are tunning now Suppressed They know what = Will cycle and what will not on = Snipers Hide

Tried it and no joy and I worked with it a lot I would not waste a bunch of time with it. It was not built for or function well with subsonic.

Thank you

what is it your thinking to try and do?
I have played some in subs not in 223

with or without cycling the action becomes the question

in anything shooting subs and cycling the action reliably semi auto are on different sides of the equation and perfect balance is hard to find

adjustable gas block helps balance the equation , find accuracy then try for function because better to hit what you want than cycle.

Without knowing what you are trying to accomplish it's not easy to specify.

Adjustable gas block and a JP silent capture buffer will give you many options