Subsonic .223 round

[Bullnettles]

Ok, this is for a suppressor I'm getting, but it has nothing to do with this thread, so I'm leaving it in rifle. I have a 1 in 7" twist on my 20" barrel. Could I load up the heaviest bullet within 100fps of going super sonic and still be accurate? I want to make this to be subsonic and still hit with at least some power. Thank you for your help.

 

[ArmedBear]

An 80 grain bullet at 1100 fps would have about the same energy as a .380.

Your best bet would be to drop that velocity just a tad to, say, 1050. Remember that .223 is a .22 with a bit more bullet weight and a LOT more velocity. Drop the velocity, and you have a fancy .22, more or less. That's not a terrible thing, but it's probably not what you'd wish for, either.

Have at it: http://www.hornady.com/ballistics-resource/ballistics-calculator

 

[cottonmouth]

I want to load some subsonic .223's too but I was thinking about going with a 35 grain HP's.

J.B.

 

[Tim the student]

If I wanted a subsonic .223, I would go with a big slow bullet vs a small slow bullet - especially if I wanted it to "still have some power".

Why do you want to use a 35 grainer cottonmouth?

 

[ArmedBear]

I want to load some subsonic .223's too but I was thinking about going with a 35 grain HP's

That will have less energy than a subsonic .22LR target round or a 36 grain HP Mini-Mag. Could work on ground squirrels. A .22LR would be a better platform, probably.

 

[SharpsDressedMan]

Subsonic .223's have always made me smile. If you go with a bullet less than 55gr, you will not get much better ballistics than a regular .22LR subsonic. Now if you have a fast twist barrel, say 1-7 or 1-8, then go with the 75-80gr bullet at 1000fps to maximize your BC, and give the maximum return on energy retention. I prefer just using subsonic rimfire ammunition, as it is just too efficient as-is, and you have a multitude of platforms to use it in (bolt rifles, semi rifles, semi handguns, etc). It is also a bit more "anonymous", and sometimes when you are silent, you also want to be discreet and anonymous. For centerfire subsonic options, a .300 Whisper maximizes subsonic and energy retention with 220-240 gr. bullets in the correct twist barrels, and can be put in those AR platforms, if needed.

 

[cottonmouth]

I figured a light hollow point would be ok, I need to find something to shoot I guess.


J.B.

 

[greyling22]

what are you going to shoot it in? last I heard you couldn't get a subsonic 223 to cycle in a semi. if you can, I want to know.

 

[KW]

Extreme shock makes a 100gr 5.56 that they claimed will cycle a suppressed AR. I seem to recall at least 1 poster on AR15.com who claimed to have used it, and that it did indeed cycle the action.

 

[benEzra]

I want to load some subsonic .223's too but I was thinking about going with a 35 grain HP's.

The easiest route to that is to get a few of those inexpensive chambers adapters and shoot .22LR subsonics. Don't forget that Aguila makes a 60gr subsonic .22LR that a 1:7 twist should stabilize fine. A .223 case with that little powder would be almost empty.

 

[Bullnettles]

Wow, thank you for all the input! I may go with the 80gr option and hope it cycles the action, and if it doesn't, then I suppose I'll just go back to super sonic because I want this to take down pigs (yes, it's legal in TX) and it's more for taking down multiples than keeping the neighbors happy. They want them gone as much as I do.

 

[KW]

You may consider trying different buffer weights - a lighter carbine buffer might make the difference in allowing it to cycle vs. a H, H2 or H3 buffer.

 

[cottonmouth]

KW, I thought about trimming a buffer spring down and seeing if it would work, my can fits on my AR's and my 10/22 but I'd just like to be able to shoot some in my AR. I have tried the .22 conversions but the twist rate is all wrong and they shoot awful from what I've seen. A 100 grain bullet might work too but I never saw any.

J.B.

 

[ArmedBear]

WRT taking down pigs, have you ever used a really heavy non-expanding bullet? They can do a bang-up job, even at subsonic velocities. Think black powder buffalo gun. The penetration of a very heavy, non-expanding bullet, even when it's just poking along, can be mind-boggling. Those old guns can kill two buffalo with one bullet, if they're standing next to each other.

An AR with a suppressed .50 Beowulf upper could make a hell of a multiple pig gun, if you have the money and inclination...

 

[strambo]

I don't have lots of experience in this area...but it seems your intended use really calls for a different caliber. .300 whisper would be a great fit, or similar. Wanting to cycle the action, be subsonic, and reliably take down a pig...is a tall order for a 80-90g .22 dia projectile at ~1000fps.

 

[RhinoDefense]

We have made 5.56 subsonic ammunition. You're better off with something that can throw more mass at the same velocity which will yield better terminal ballistics. Any serious bullet used in subsonic applications should be in the 200gr or heavier spectrum. A 150gr anything is really pushing the limit but that's what I call the "50 yard only" weight.

Something what you're after I would suggest getting a .300 Whisper and start reloading or buy in bulk from a company that makes it available for purchase.

 

[renner8592]

subsonic .223

It would seem to me that you'd need a dedicated upper to shoot subsonic .223 with a suppressor.

I'd start with a moderately heavy hollow point round like a flattail 65, shot from a sort (12" to 16") relatively high twist rate barrel; something like 1:12 to 1:17, with a relatively fast burning power.

Getting the right powder would be all trial and error. You'd need reasonably low pressures shot from a short barrel that reach speeds between 1000 and 1100 fps; a balancing act at best that would have to be done on a test-bench having the expectation of blowing up at least a couple receivers before getting it right.
Oh and by the way, if anyone ever trys to tell you to put 8gr of ANY powder into a .223 case, you'll know right away they're clueless about putting something like this together..... Geeez.

A dedicated platform would be needed because you'd have to have a specialized barrel with a higher than normal twist rate WITH an enlarged gas port so the system would cycle, but this wouldn't work with anything else and still stay together after ten rounds or so. Otherwise, you're better off going with a bolt action weapon because it doesn't make any sense using the m16 platform unless you need a semi or full auto silenced weapon. Also, it's the gas port size that regulates the cycle rate etc, not springs, buffers or fairy dust.

I'm sure it's been done before for some CQB unit somewhere. It wouldn't be hard for any reasonably competent armorer/gunsmith to put it together in a week or so, but if you're thinking of doing something like this on your own, you should know there's another name for something like this, it's called a BOMB!

 

[jmorris]

I want to make this to be subsonic and still hit with at least some power.

You have the wrong upper you need a 458 or 50 using 400+ grain bullets. You have to have speed or mass, if you do away with both say bye bye to energy.

 

[ironhead7544]

Subsonics are being loaded with Trail Boss these days. High bulk works well. I dont know about 223 but 308 with 180-200 grain bullets seem to work best. I would do a search and you should be able to find some reloading info. I think someone is making an adjustable gas systems for autoloaders but dont know about 223s. Twist may be a problem. For the 308 at 1050 in a 1 in 10 twist the short round nose 180-200 stabilizes OK. You will have to experiment to find the best load for your individual rifle.

 

[taliv]

Do a search in the reloading forum. You'll find a lot mor threads on subsonic 223 there

 

[SharpsDressedMan]

Get a 300 Whisper upper if you are using an AR. Also, a .30 cal suppressor can be used on a .223, but not the other way arround. A 220 grain bullet at 1050 is the way to go on pigs, etc.