.223 Subsonic Loads Experience

[jhr]

Hello all,

New to the forum but I did try searching extensively before posting this so please go easy on me.

I'm looking for others' experiences with very heavy (100+ gr) .223 bullets for subsonic only use, able to be fed reliably through an AR magazine. Semi auto operation is not required but would be a bonus. (I know taliv and 444 have done some experimentation in this area...)

Not interested in a 22LR conversion either. I specifically want to fire subsonic .223 loads using a 1:7" twist barrel that pack a little more punch than 22LR while still remaining subsonic and without having to swap bolts, etc.

I've heard some say 100 gr have been successfully used, but very few details on bullet type/manufacturer, powder, etc. were provided. I can't even find a mold company that sells molds for casting .223 bullets anywhere close to 100 gr. Feels like I'm searching for a unicorn.

Not sure why this information seems to be so elusive or closely guarded, but if you have any experience successfully developing accurate heavy weight subsonic .223 loads, please share.

Thank you in advance.

 

[plmitch]

What size bullets/powder combinations have you tried so far? What barrel are you shooting?

 

[jhr]

I haven't tried any yet. Still trying to find out what is feasible based on others experiences. I'd like to use as short a barrel as possible. I've read 12.5" suggested as a minimum but I'm very interested in what others have had success with.

 

[Centurian22]

Have you looked into .300 blackout at all? .223 brass, cut down and re-necked to accept a .308 bullet, can be loaded super or sub sonic. Subsonics are usually 220gr I believe. Only change from a standard AR is the barrel all other components stay the same. I've heard it does very well in short barrels and with suppressors.

I unfortunately am of no help with .223 bullets heavier than about 80gr or keeping them subsonic. Have you looked into Trailboss as a powder? It will not cycle the semi auto most likely but does give safe reduced loads. Might be subsonic I'm not sure.

 

[BackCountry]

This may not be what you are looking for but I use 3 - 5 gr Green Dot with 55 gr .223 bullets to produce accurate sub sonic rounds for shooting Beaver in my back yard with my AR - 15. Does not cycle the gun obviously but makes much less noise than a .22 LR.

I have a psychotic anti-everything neighbor who hates me killing the beaver that cause very expensive damage to my irrigation ditches and water rights so we have to eliminate them. I used to use a shotgun but she would call the sheriff every time I removed a beaver. The sheriff would just turn around and charge her with harassment and fine her but she never learns. Easier to use sub sonic .223 to take care of the problem and not disturb the crazy woman... As long as I am not firing in the direction of her property she can't hear it and the sub sonic .223 are as effective as Buck Shot and cheaper.

 

[jhr]

Thanks, BackCountry, that's good to know.

Centurian22, a .300 blackout is definitely in my future, but I still want to know how far the .223 subsonic load can realistically be taken in an AR platform.

 

[rcmodel]

some say 100 gr and even as much as 150 gr bullets have been successfully used, but no further details such as bullet type, powder, etc. were provided.

The rifling twist necessary to stabilize a .224", 150 grain bullet that long at subsonic speed would be on the order of a 1:4" twist.

No way a typical 1:7 or 1:9 twist would stabilize anything that heavy.

rc

 

[jhr]

Thanks, rcmodel. I guess I should have stated one of my assumptions was a 1:7 twist. I thought the same thing when I read about the 150 gr bullets. If I recall correctly, I believe they were made from tungsten or depleted uranium and only used by the military. So assuming the next densest material someone like me would be able to use is plain old lead, what's the heaviest .223 lead bullet anyone has heard being fed through a 1:7 twist AR at subsonic speeds?

 

[Mule]

experiences with very heavy (100+ gr) .223 bullets for subsonic only use, able to be fed reliably through an AR magazine.

Long, heavy bullets may not be compatible with standard AR magazines. Pushing the bullet too deep into the case reduces powder capacity and elevates pressures. Proceed with caution.

 

[clearcut]

Can you shoot lead in a AR with gas ports? I don't use lead in my desert eagle for fear of clogging gas ports.Why do you want sub loads?
CC

 

[KansasSasquatch]

Some people on here claim to use hard cast bullets in an AR. I wouldn't want to try doing on a regular basis, especially without gas checks.