I don't mess with subsonic 223, its a waste of time for me to try to turn my 223/556 into a. For my 308 bolt gun,I prefer to make my sub rounds out of trailboss, which is very bulky and provides a much better case fill. I personally have not migrated to using it yet though. Probably not the best explanation, but TG almost seems impervious to this, so it has gained ground as a subsonic powder. Small amounts of most powders will usually provide huge pressure spikes because of a flashover inside the case. TG has gained popularity because of its ability to not be position sensitive. Hornady's hit the target sideways, will NOT stabilize in the 9 twist barrel. Now, I have tried them in a 9 twist bolt action rifle, super quiet with the suppressor, but the 75 gr. Sierra GK with a 5.2 gr, charge of Trailboss. I chrono them at 1050 fps with good accuracy at 50 yds. I can't remember the exact load amount, but around 5.4g or so. Hornady BTHP loaded over Trailboss powder. Light buffer spring (NEMO) and a Form 1 suppressor. 223 subs to cycle an AR type pistol and here is what works for me:ħ1/2' AR, Pistol gas barrel (7 twist) with the gas port drilled to. It would still be cool to get 1500 rounds out of a pound though.įor what it's worth, I took on the feat of building. I am sure you could get it to cycle if you worked it up but like Mark said it will be hard to get enough gas built up before it peaks. I have read some posts on other forums about this load, it will not cycle an AR, built to shoot on a bolt gun. There's no way around that with a subsonic bullet. But it's a cartridge designed for the AR to cycle, be accurate and be subsonic. There is another cartridge, basically a stolen version of the. 223 based cartridge that does this, it's called the. You'd need to use a powder slow enough, and enough of it to allow sufficient pressure at the gas port, and a bullet heavy enough to act as a cork, to again, allow the pressure. 223 be achieved that will cycle a 5.56 AR? Maybe if one could load a 150-200 grain bullet. I've experienced enough lodged bullets and they aren't fun.Ĭan a subsonic. Can one use light bullets in subsonic AR loadings? Probably, but I won't. In guns w/o a gas port I use lightweight bullets for subsonic. I know the 100 yard group was terrible because the bullet has destabilized. That was many years ago that I did that work and some of it is sharp and some is fuzzy. At 100 yards the bullets are keyholing and groups were around 4' if I remember correctly. It was a tackdriver out to 75 yards but with a rainbow trajectory. I think my subsonic AR load used Green Dot and i know it used a Sierra 70 gr. I also don't like using really fast powder. Of course with guns having a gas port near the muzzle, or entirely absent, that possibility is greatly reduced or eliminated. You also won't experience lodged bullets in the barrel. You'll hear it (or not hear it) when you go subsonic. I suggest that they start slightly higher, into the super sonic range and work down. Oh, and you had better know what you're doing. So to counteract this I tell folks to do exactly the opposite of what is suggested when loading. If too little velocity is attained or the bullet is too light the bullet doesn't exit the barrel and the pressure can be heard to FFZZZZZ as it leaks out the port. We're not dealing with much pressure when using fast powder in the 5.56/.223 when the bullet reaches the gas port. I like my subsonic loads to use a heavy bullet for the AR. The problem with subsonic loads in an AR is the gas port in the barrel. Sure it could be fired out of an SBR or handgun, but it'll never reach much above subsonic and be safe. Mark got it right, subsonic and not normal 5.56/.223 velocity.

Subsonic 223 loads powder