well some time back I went down this rabbit hole with 7.62x39mm and then with .308 lots of fun but after having both rifles do slight baffle strike I gave up on that idea
now MANY MANY folks have asked about subsonic in .223...FINNALLY found hard data from Hornady...4grns trail boss behind a 55grn fmj
wanted to try in .222rem so poked 3.5grns in behind a 60grn projectile which I took tip off with bench grinder so it was nice n square..they are scarely quiet..the whollop of projectile hitting puddle 70ish yards away was louder than the shot
now I will not recomend using these on anything bigger than a hare/rabbit/possum/wallaby/young goat/young pig at under 50 yards..BUT they will be fun for plinking and great for finishing off ,back of ear type shots. expansion will be minimal...IF you can find some .22magnum projectiles,give them a whirl,they should be ideal.

Interesting. I might have to buy a 222 to try this. There is a pile of 60 gr projectiles in the cupboard, may have found a use for them. I just sold Nat's guns as she was the only one in the family that was a lefty - a nice 223 A Bolt with beautiful wood stock was one of them. Almost kept it because of the wood but in the end decided to sell them and get her girls something that they can shoot. I have two new shooters over 30 yrs of age to bring along, one is married to a shooter so he will do most of the work I'll supply the tools.

I've been thinking about a suppressed .350 Legend bolt action. Hornady makes a 250 grain "Sub-X" bullet. I've already got an AR in .350.

You know, to go with the rest of my partially completed projects...

unless you are right next to houses....or THINK you will get more than 2-3 chances at mob of hogs before rest flee....going subsonic is ,well ..... a giant leap backwards. now a fully suppressed barrel,like the early savage rifles have,that completelt cover barrel and have lots of porting are interesting,they really do quieten down supers...actually any large capacity can does,one of the best suppressors is made by DPT its in modules and you can keep adding baffles till you get degree of suppression you want or weight you no longer happy to cart around LOL. most have 3 baffles but guys are running up to 8.
my SUGGESTION to you is this..try the subsonic rounds in gun you already use....and see if terminal results are something you comfortable with before going any further..there are a LOT of 2nd hand suppressed set ups forsale as guys got them,tried them,lost animals and gave up on whole idea. a subsonic round non suppressed is still a lot quieter than a super.

Evis, I agree that subsonic isn't the best way to go for hunting. I don't see the point in limiting the effectiveness by limiting the velocity. That said, my stuff would just be another toy to play with, hence the bolt gun, which would be quieter than a semi-auto.

If I'm seriously hunting I'll break out Ol' Splintermaker!

Elvis - I know your comment was directed at Mike. We can not have suppressors here so a sub load sounds interesting for the noise reduction. More as a play thing than anything but could be used at questionable hours on the odd coyote that wanders too close in to the yard.

This is a chart I put together showing how much bullet weight you need to reach a particular muzzle energy at subsonic velocity, 1050 ft/sec. I picked 1050 to keep things subsonic and allow for velocity variations due to heat, etc. For example, if you want 500 ftlbs of ME you need a 204.3 grain bullet.

Suppressors not allowed here, so if you want “quiet” loads it’s a case of sub-sonic factory rounds, or develop something yourself.

A mate and myself played with cast sub-sonic loads for a number of calibres (.223 REM, .243 Win, 30.30 Win, .308 Win, 8mm Mauser). We developed fairly accurate cast loads, but I wouldn’t say that the noise was greatly reduced. The only things we did find was…the loads were reasonably cheap to produce and the recoil was significantly reduced.

These loads were really only produced for cheap plinking, more so at the range than anything else, but as for hunting, they would only be used at about 75m max, and then only on small game about rabbit sized. Having said that, a .30 calibre or 8mm projectile even at sub-sonic speeds is a sizeable lump of lead that can’t be “argued” with when headed your way.

From memory, Gelan is the guru of sub-sonic, with the development he did with his 45.70…very accurate and hit like a freight train.

Cat sneezes are an awesome thing to shoot, almost no recoil and are good to the ears.
Fast powder burns completely in the barrel is the aim for best result.

Frankly I have not been loading much lately.
The supplies are scarce in Australia, primers are now about $200 a thousand and powders (if you can find them) are over $250 a pound.
Trailboss and fast (pistol) powder is unobtainium to the point that to do my last IPSC I have been cutting out cheap shotgun shells to get the powder to load my 9mm.
Death of a thousand cut indeed.

Im sorry to hear that Gelandangan......there is two part used containers of shotgun powder in shed and a near full one of trailboss.... the shotgun powder will take a LONG time to be used up at 6 grns per load in .44magnum,if I could get it to you I would in a heartbeat...same deal on reason for that quiet load...mate uses it for possums when pighunting LOL
Trailboss not being made at moment.... but you can still get sulphur and salt petre and plenty of willows around the place...not sure how it would go in 9mm...... would get a few looks at the range no doubt....

I’m finding the same problems as Gelan…components are scarce (powders I can’t understand because they are manufactured here in Australia) and when they do become available, they are so damned expensive it’s not even remotely funny.

I see the problem with the cost being twofold…

1. The soft male chooks, that subscribe to OH&S, have made it so expensive to move powders it’s beyond comprehension. The extra cost attached to Dangerous Cargo, and the limits of what can be carried, is ludicrous.

2. The greed of everyone in the supply line, up to and including the sales outlets. Although, to be fair, they are only passing on their extra costs…plus their profit margin.

Standby, rumors are circulating that powder is going to be going up another 25% more because of all the powder ingredients going to ammo and shells being sent to Ukraine.

we all have more than enough to last us for HUNTING untill we shuffle off this mortal world..we do not however have the surplus needed for long days plinking or punching paper....and watching videos from your part of the world Slim....guys using mini gun at 70000rounds per minute to shoot AT hogs from a dune buggy...yeah well its easy to see why in places supply may run low.
videos of impromto ranges where a drone is flown back n forwards untill finnally brought down with 20-30 people all blazing away with everything from revolvers to full blown antiaircraft cannon,are reasonably common and easy to find. fuel for scardypants ANTIs and sure doesnt show shooting community in good light,cooking bacon on suppressor via a mag dump....yeah nah.... just dumb stuff.
why does the price go up you ask???? the same as petrol and diesel..our governments tax sales on a PERCENTAGE basis,not a per round /per litre basis so any increase in sale price means an increase in the tax take.....why kill the goose that lays the golden egg......system is rigged so the house always win...the higher the price the better for them,it also goes towards reducing civilian usage..the end game on both fronts.