I decided to mess around with subsonic and .223 today, mostly out of boredom.

I did a workdown using Titegroup, as that is what I found for a subsonic Hornady recipe.

I ended up with:

55gr VMAX seated to 2.2"OAL over 3.1 grains of Titegroup. Light crimp to finish them off.

They don't cycle, but from my testing and understanding, subsonic .223 will never cycle (unless major mods). They are ridiculously quiet - FPS is right at 1050.

Are they worth it? No. Probably not. It's basically a very expensive .22 and not really worth the effort or materials. But I wanted to try, and the results are pretty neat.

I'll just save em and use em for rabbit when I go out hunting.

Attached File


I shot them out of a 16" Ruger 556. Stock barrel. Geissele internals, and a Toolcraft BCG. Carbine gas system. This rifle came with a FSB and a "Delta" ring. I cut the FSB and installed a freefloat handguard.

Attached File


Here is the result video. It's rainy and dead quiet outside where I live.

https://youtube.com/shorts/3WmaxDBXClY?feature=share

I did the same with 55 Nosler Ballistic tip varmints,  and 4 grains of trail boss.. shot through a 12.5 in with an NT4 on it… SUPER quiet. I shot one into water filled milk jugs, about 6 feet away, it went through 2, came to rest in the third, and only had the engraving from the rifling.. not a hint of expansion etc. nothing.  I have some other varmint type bullets I want to try though. Grouped surprisingly well at 25 yds. Enough to hit squirrels with.. so there’s that.

I wouldn't expect any expansion out of mine either. Too slow to get the real vmax effect but yeah, good enough for rabbits I'm sure. I didn't load a ton of them, so I'll just save em for small game on the back 40

You're giving me ideas for new loads to try out in my Ruger American Ranch 5.56 bolt gun.  Maybe I'll try it with a 77gr SMK and see how quiet it is through my old Surefire suppressor.  I've got some Titegroup and Unique on the shelf...might try to find some Trailboss.

My first thought was a heavy projectile like 300blk.

I tried a load-down with 69gr bullets. They work, but they were keyholing at 15 yards. It seemed like at these really low velocities for .223, the heavy projectiles destabilized really really fast.

The lighter 55gr ones behaved better, no keyholing at 20 yards.

That was out of a 16" AR, 1in7 twist. Yours may behave differently.

Can confirm squirrels and armadillos go down way faster than with a 22 short. And quieter. ?? also a 220 subsonic in a 300BO will drop a squirrel immediately… ?? and also quietly.

I loaded up a bunch, and a bunch with 55 FMJ’s, way too much fun to shoot. After awhile some things get boring so mixing it up with these makes it fun again. Have a handful of 50gr dogtowns and some 52gr Speer varmints to try. Even if those don’t expand, they will still get it done.

Hornady I think published the load data....

I've done  3.5gr of TG for 223 with 62gr FMJs, real quite out of a 26" barreled bolt gun, dead silent in a buddy's varmint AR wtih can, didn't cycle action of course.

I've also seen published data using (iirc) 5744 and getting 50-60 grain bullets up to 22wmr velocities (1800-2000fps)

And I did my 762x39 mousefarts - 85gr 32acp pistol bullet (well, .312" 85gr Hornady XTP) over 4.0gr titegroup gave just at 1000fps and fairly accurate at 50 yards.  When I was working this one up I noticed that with 3.0 and 3.5 gr charges I had much larger swings in velocity and spreads,

I always figured a subsonic .223 load would shine with a super heavy bullet, that could possibly be seated very deep to fit in box mags, and would probably work on critters under 100lbs.

Big chonker of a cast HP maybe? Or go all out with a OTM oriented to long range.

See my post above, but I had really bad results with heavier bullets going subsonic through a 16" AR. I've had far better success taking a light bullet, down-loading the powder to teeny tiny amounts, and seating that mf'er deep as she'll go.

I read about backwards seating. It made me a little nervous as that is a totally new tangent of reloading that I'm not comfortable attempting yet. Maybe if I had a sacrificial barrel and receiver I'd be willing to try.

I know that was something done many decades ago, to play with older load dynamics. I just haven't tried it nor do I really want to.

I guess I failed in the OP to mention that I used magnum primers. I had bought a large amount of small rifle primers from a personal sale quite a few years ago, and failed to realize that there were two boxes of Magnum Small Rifle mixed in there. I had primed a 50 count of brass before I realized that they were magnum.

I didn't know what I was gonna do with the primed cases...nothing I ever use called for Magnum primer'd .223, so I just put em in a box and sat on them for a long time.

I figured with a .223 subsonic load, the magnum primer A. would help with completely burning all 3.1 grains of TG, B. would use up these rounds without me having to waste them, and C. Wouldn't make a difference at all anyways on a sub load.

I use magnum primers in everything except my 6xc…

Oh...lol.

I've only ever used standard