.223 Subsonic twist rate?

[Fritzcat]

I have done some shooting with my 223s and not nailed a load yet. It is fun and cheap to plink with. I have also used the 22lr conversion in some of my ARs and sub-sonic with acceptable results.

[kanton]

Does anyone make a .223 reduced capacity case for subsonic use? Is there any way of easily and safely reducing the capacity of the standard case?

[ohnomrbillk]

1 in 9 works on rimfire 60gr bullets at subsonic speeds. I was recommended a 1 in 7 for 80 and 90 grain at supersonic speeds. If you are wanting those, I would suggest a tighter twist for subsonic than 1 in 7".

I asked JD Jones about it recently, as I was interested in a 22 whisper. He said they have made a bunch on the 22 hornet as well as the 5.7 FN round. He also was quick to point out the 22 SSS rimfire ammo with the right twist makes a lot of sense for less money.

I'm looking for the right bolt action 22 hornet, and have hopes to exceed the accuracy and range of the 22 SSS. Now if I can just come up with an old BRNO in 22 hornet for the right price....

[i8asquirrel]

I have not tried .223 subsonic but I shoot a 5.7x28 with 60gr. Vmax over 2.7 gr of Hodgin Clays. I fire it through a 22lt can from a Ar57 works great

[alorton]

Originally Posted by libertyman777

Hey Lou,

I'm not choosing it over .300 Whisper, I"m including it along with .308 for use with my .30 caliber can (when I buy it). I plan on threading every barrel that I buy for my Savage that is .30 and under. I know that subsonic .223 will not be as quiet as it could be out of a dedicated .223 can and most of the time, I'll be shooting supersonic with the can in place but I was hoping that I could buy a barrel in a twist rate that would allow good performance either way.

I didn't understand part of your answer . Could you elaborate?

Thanks,

Paul

What he was referring to is the tendency to see larger velocity dispersion in a case that has a small percentage of the volume filled by powder and/or bullet. It is why the 300 Whisper is good for subsonics. It has a very small case and with the larger .308 bullets there is very little open space when it is loaded, making it ideal. If you shoot .308 Win subsonic, which is definitely possible, you will see a larger variation in the velocity from round to round. For this reason, you'll have to load to a lower average velocity to make sure all rounds are subsonic and will get some vertical stringing because of it at longer ranges.

[fpjeepy05]

Originally Posted by Spook

I corresponded with a guy who's "22 whisper" was a 22 hornet that he used to shoot whitetails through the lungs.He claimed it was very effective by virtue of the long bullets tendency to yaw at impact.

I haven't even gotten my 300/221 fully pieced together and I'm already dreaming about the next one. TC contender 1/6.5" twist .22 K-Hornet, shooting 90gr SMK's ... beautiful. Would the would this case support the 90gr pills. What is the program that everyone uses for calculating muzzle velocities off case capacity, powder, bullet weight etc? And a ballistics Calculator? Anyone got any pictures of such a round? I imagine it would be mostly just for plinking and/or varmint.